The hemp, cannabis, and functional mushroom industries have invented and reused enough specialized vocabulary to fill a small dictionary. This glossary defines more than 30 of the most important terms a consumer or industry professional will encounter, with brief, plain-language explanations.
A
Adaptogen
A natural substance, usually a plant or fungus, traditionally believed to help the body adapt to stress and maintain balance. Functional mushrooms like Reishi, Cordyceps, and Lion's Mane are commonly grouped as adaptogens, alongside herbs like ashwagandha and rhodiola. The term comes from Soviet research in the 1940s and 1950s.
B
Beta-glucans
A class of polysaccharides (long-chain sugars) found in the cell walls of fungi, oats, barley, and yeast. Beta-glucans are responsible for many of the immune-modulating effects of functional mushrooms. The amount and structure of beta-glucans, especially the beta-1,3 and beta-1,6 forms, is a primary indicator of mushroom extract quality.
Bioavailability
The percentage of a compound that actually reaches your bloodstream after consumption. A CBD tincture taken sublingually has higher bioavailability (around 20 to 35 percent) than the same milligram dose taken as a gummy (around 4 to 20 percent), because edibles are subject to first-pass metabolism in the liver.
Broad Spectrum
A type of hemp extract that contains a range of cannabinoids and terpenes but has had THC removed through additional processing. Broad spectrum products aim to deliver entourage benefits without the THC liability that full spectrum products carry on drug tests.
C
Cannabinoid
A chemical compound that interacts with the endocannabinoid system. Phytocannabinoids are produced by plants (THC, CBD, CBG, CBN, etc.). Endocannabinoids are produced by the body (anandamide, 2-AG). Synthetic cannabinoids are made in laboratories.
CBD (Cannabidiol)
A non-intoxicating cannabinoid that is the most studied compound in the hemp industry. Used for stress, sleep, soreness, and skin care, with FDA approval (as Epidiolex) for two rare seizure disorders. Federally legal in the United States when derived from hemp.
CBG (Cannabigerol)
A non-intoxicating minor cannabinoid sometimes called the "mother cannabinoid" because most other cannabinoids start as CBGA in the live plant. Studied for focus, gut health, and antibacterial activity. CBG-dominant products are typically more expensive than CBD because the plant produces less of it.
CBN (Cannabinol)
A mildly psychoactive cannabinoid that forms when THC ages and oxidizes. Best known for sedative effects and commonly used in sleep formulations, often paired with CBD or melatonin.
COA (Certificate of Analysis)
A laboratory document that lists the cannabinoid profile and contaminant testing results for a specific batch of a hemp or cannabis product. A trustworthy COA comes from an accredited third party lab, includes batch numbers, and reports both cannabinoids and contaminants like pesticides, heavy metals, microbials, and residual solvents.
Cordyceps
A functional mushroom (most commonly Cordyceps militaris in commercial products) studied for cellular energy, oxygen utilization, and exercise performance. The active compound cordycepin is structurally similar to adenosine, the building block of ATP.
D
Decarboxylation
The chemical reaction that turns THCA into Delta-9 THC by removing a carboxyl group, typically through heat. Decarboxylation happens automatically when cannabis is smoked, vaped, or baked into edibles. Roughly 87.7 percent of THCA converts to active THC during efficient decarboxylation.
Delta-8 THC
A mildly psychoactive cannabinoid that is a chemical isomer of Delta-9 THC. Almost always synthesized from CBD through isomerization rather than extracted directly from the plant. Federally legal under the Farm Bill loophole, but banned or restricted in more than 20 US states.
Delta-9 THC
The classic intoxicating cannabinoid in cannabis. Schedule I controlled substance under federal law in the United States, but legal recreationally or medically in many states. The 0.3 percent Delta-9 THC threshold defines the legal line between hemp and marijuana.
E
Endocannabinoid System (ECS)
A body-wide signaling network that helps regulate sleep, mood, appetite, immune response, pain, and stress. The ECS includes CB1 receptors (mostly in the brain and central nervous system), CB2 receptors (mostly in the immune system), endocannabinoids produced by the body, and the enzymes that synthesize and break them down.
Entourage Effect
The theory that cannabinoids and terpenes work better together than alone, producing effects that pure isolated compounds cannot replicate. Used to explain why full spectrum products often outperform isolates and why different cannabis strains feel different at the same THC content.
F
Farm Bill (2018)
The Agriculture Improvement Act of 2018, the federal law that legalized hemp in the United States by defining hemp as cannabis containing 0.3 percent or less Delta-9 THC by dry weight. The Farm Bill made hemp-derived CBD federally legal and inadvertently created the legal foundation for Delta-8, THCA flower, and other hemp-derived intoxicants.
Fruiting Body
The reproductive part of a fungus, what most people picture when they think of a mushroom. Premium functional mushroom products use fruiting body extracts, which contain the highest concentrations of bioactive compounds. Compare to mycelium, the vegetative root-like network of the fungus, which is cheaper to grow but produces less potent extracts.
Full Spectrum
A type of hemp extract that contains the complete cannabinoid and terpene profile of the source plant, including up to 0.3 percent Delta-9 THC. Considered the strongest expression of the entourage effect, but carries some risk on drug tests with regular use.
H
Hemp
Cannabis sativa containing 0.3 percent or less Delta-9 THC by dry weight, defined federally by the 2018 Farm Bill. Used for fiber, seed, building materials, and cannabinoid extraction. Botanically the same plant as marijuana, but legally distinct.
I
Isolate
A purified single cannabinoid, usually 99 percent or higher purity, with no other cannabinoids or terpenes present. CBD isolate is the most common, sold as a white crystalline powder or formulated into oils, gummies, and topicals. No entourage effect, but the most predictable and drug-test-safe format.
L
Lion's Mane
A functional mushroom (Hericium erinaceus) studied for cognitive support, focus, memory, and nerve health. The active compounds (hericenones in the fruiting body, erinacines in the mycelium) stimulate the production of nerve growth factor.
M
Marijuana
Cannabis sativa containing more than 0.3 percent Delta-9 THC by dry weight. Schedule I controlled substance under federal law in the United States. Legal recreationally or medically in many states under state-specific programs. Botanically the same plant as hemp, but legally distinct.
Mycelium
The vegetative root-like network of a fungus that grows beneath the surface of the substrate. In commercial mushroom supplements, mycelium grown on grain is cheaper to produce than fruiting body extracts but contains lower concentrations of beta-glucans and active compounds, and often includes residual grain starch.
R
Reishi
A functional mushroom (Ganoderma lucidum) used for thousands of years in traditional Chinese medicine. Studied for immune modulation, sleep support, and stress recovery. Rich in beta-glucans and triterpenes including ganoderic acids.
T
Terpenes
Aromatic oils that give cannabis (and many other plants) their smell and flavor. Major cannabis terpenes include myrcene, limonene, pinene, linalool, caryophyllene, humulene, and terpinolene. Terpenes are pharmacologically active and contribute meaningfully to the entourage effect.
THC
See Delta-9 THC.
THCA (Tetrahydrocannabinolic Acid)
The non-psychoactive precursor to THC found in raw, unheated cannabis. Converts to Delta-9 THC through decarboxylation when heated. Hemp flower with high THCA content but low Delta-9 THC at harvest can qualify as federal hemp while still producing intoxicating effects when smoked.
THCV (Tetrahydrocannabivarin)
A minor cannabinoid that is structurally similar to THC but with different effects. At low doses, THCV is non-intoxicating and is studied for appetite suppression and metabolic effects. At higher doses, it can be mildly psychoactive.
Total THC
A measurement of psychoactive THC potential in a cannabis sample, calculated as Delta-9 THC plus 87.7 percent of THCA (representing the realistic post-decarboxylation conversion). Some states use a total THC standard for hemp testing, which can disqualify high-THCA flower from the hemp category.
Trichomes
The resin glands on cannabis flowers that produce most of the plant's cannabinoids and terpenes. Trichomes look like tiny mushroom-shaped crystals coating the surface of cannabis buds and small leaves.
Triterpenes
A class of bioactive compounds found in functional mushrooms, especially Reishi and Chaga, contributing to their bitter taste and many of their immune and anti-inflammatory effects. Distinct from beta-glucans, which are the other major active compound class in functional mushrooms.
Turkey Tail
A functional mushroom (Trametes versicolor) with the strongest clinical evidence base of any consumer-market mushroom, including approved adjunctive cancer therapies in Asia. Most associated with immune support and gut health.
C (continued)
Chaga
A functional mushroom (Inonotus obliquus) that grows on birch trees in cold northern forests. One of the highest natural sources of antioxidants by ORAC score. Used in traditional Russian and Siberian medicine for centuries for general health and immune support.
Final Note
The hemp and functional mushroom industries continue to evolve, and so does the vocabulary. New cannabinoids, new mushroom species, and new extraction methods are entering the market faster than regulators or dictionaries can keep up. When you encounter a term you do not recognize, ask the brand to explain it. Brands that cannot define their own terms, or that hide behind technical-sounding language, are usually selling something thinner than the words suggest.