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

Secondhand marijuana smoke has many of the same carcinogens and toxic chemicals as secondhand tobacco smoke, along with THC, the active ingredient in cannabis. —David Stempel, The Mercury News, 9 Nov. 2024

The 2018 farm bill, for example, legalized hemp, which inadvertently popularized delta-8 THC. —Marin Cogan, Vox, 4 Nov. 2024

Nelson’s daily dose of THC is about sixty milligrams—enough to turn a regular person into stardust. —Adam Iscoe, The New Yorker, 4 Nov. 2024

Because of this similarity, THC is able to attach to molecules called cannabinoid receptors on neurons in these brain areas and activate them, changing various mental and physical functions. —Lisa M. Krieger, The Mercury News, 28 Oct. 2024

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