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

In a way, that complexity has pushed us to broaden the portfolio and position Goodmellow as a functional beverage brand, not just a THC beverage. —Jeff Burkhart, Mercury News, 18 Mar. 2026

The book explores the intricacies of farming weed and extracting THC oils as well as California’s drug laws. —Stuart Miller, Oc Register, 18 Mar. 2026

Defense lawyers also scrutinized the handling of evidence collected from the home where Eric Richins died, including phones, THC gummies and items mapped during a 3D scan of the residence. —Stepheny Price, FOXNews.com, 17 Mar. 2026

One take-home message from their work is an emphasis on the dose — that high THC-containing products like gummies and concentrates, especially for those who have a serious mental illness, appear to carry the most risks. —Will Stone, NPR, 17 Mar. 2026

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