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

The provision in the shutdown bill prohibits products containing more than a certain amount of THC, the psychoactive compound in cannabis and hemp, per container. —Andrew Edgecliffe-Johnson, semafor.com, 21 Nov. 2025

My neighborhood liquor store has an entire cooler full of weed drinks, including a seltzer aptly named Bong Water, a can of which has 25 milligrams of THC. —Nicholas Florko, The Atlantic, 21 Nov. 2025

The only products left standing would be ones that contain virtually no THC and industrial hemp. —Gina Lee Castro, jsonline.com, 20 Nov. 2025

Authorities found additional food items suspected of containing THC in McGillem's possession, the sheriff’s office alleged. —Kc Baker, PEOPLE, 17 Nov. 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