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

Police said 22 students ingested edibles containing THC. —Mandy Taheri, MSNBC Newsweek, 14 May 2025

Various chemicals come from cannabis, with the most commonly discussed being THC. —Joseph States, Chicago Tribune, 12 May 2025

Long before the current controversy erupted, there was a massive legal battle brewing over ownership of THC and how Garib Karapetyan became an owner of the shop. —Sam Stanton, Sacbee.com, 8 May 2025

In smoke shops, consumers might find questionable products made with chemicals such as Delta 8 THC, Delta 10 THC, THC-P and THC-0, Keller says. —Ron Hurtibise, Sun Sentinel, 2 May 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