THC

noun

ˌtē-(ˌ)āch-ˈsē 

: either of two physiologically active isomers C₂₁H₃₀O₂ from hemp plant resin

especially : one that is the chief intoxicant in marijuana

When a person tokes, eats or vapes cannabis, a wave of THC, or tetrahydrocannabinol, washes into the brain.

—Laura Sanders

THC, the main chemical component of marijuana, has been shown to reduce nausea and increase appetite in chemotherapy patients.

—Andrew Weil

THC disappears from blood quickly as it is absorbed in the brain, making blood tests a more reliable measure of recent use but not a great correlate of impairment.

—Eliza Gray

Examples of THC in a Sentence

Recent Examples on the Web

Other events on Halloween night CONNIE'S − Cover band Werewolf Bar Mitzvah starts at 9:30 p.m. There will be drink specials from Cornbread THC Seltzer, Nelson’s Greenbrier, Liquid Death, 3 Floyds Brewing, and Mirat. —Keith Sharon, Nashville Tennessean, 30 Oct. 2025

As a fan of rich, dark fruit, my personal favorite is the juicy Black Currant seltzer, but those who prefer something citrusy should try the delightfully tart Ruby Grapefruit, both made with 5 mg THC and 10 mg CBD. —Chala June, Bon Appetit Magazine, 29 Oct. 2025

While the legality and regulation of THC products varies on a state-by-state basis, some states have reportedly banned items that are packaged similarly to candy. —Julia Bonavita, FOXNews.com, 29 Oct. 2025

Elmahdi is being charged with operating while intoxicated with passengers under 16 years of age, possession of THC, reckless driving endangering safety, operating while suspended, operating without insurance and a child safety restraint violation. —Anna Kleiber, jsonline.com, 27 Oct. 2025

Word History

Etymology

tetrahydrocannabinol

First Known Use

1967, in the meaning defined above

Medical Definition

THC

noun

ˌtē-ˌāch-ˈsē 

: either of two physiologically active isomers C₂₁H₃₀O₂ that occur naturally in hemp plant resin or are synthetically prepared:

a

: one that is the chief intoxicant in marijuana and is used medicinally

called also delta-9-tetrahydrocannabinol, delta-9-THC

see dronabinol

b

: one that is present in marijuana only in minute quantities