: 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 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 Wisconsin public health officials are urging customers who bought pizza from a local restaurant this week to throw it out, after the pizzas were found to have been contaminated with THC. Charlotte Phillipp, People.com, 27 Oct. 2024 Similarly, Sativex, which contains both THC and CBD, is prescribed for spasticity due to multiple sclerosis. Calvin Rasode, Rolling Stone, 25 Oct. 2024 Officials said the oil in a container used to make the pizza tested positive for THC. Drake Bentley, Journal Sentinel, 24 Oct. 2024 See all Example Sentences for THC 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'THC.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

tetrahydrocannabinol

First Known Use

1967, in the meaning defined above

Time Traveler
The first known use of THC was in 1967

Dictionary Entries Near THC

Cite this Entry

“THC.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/THC. Accessed 5 Nov. 2024.

Medical Definition

: 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

More from Merriam-Webster on THC

Last Updated: - Updated example sentences
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