L-tryptophan

noun

L-tryp·​to·​phan ˈel-ˈtrip-tə-ˌfan How to pronounce L-tryptophan (audio)
: the levorotatory form of tryptophan that is a precursor of serotonin and was used formerly as a dietary supplement especially to promote sleep and relieve depression

Word History

First Known Use

1949, in the meaning defined above

Time Traveler
The first known use of L-tryptophan was in 1949

Dictionary Entries Near L-tryptophan

Cite this Entry

“L-tryptophan.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/L-tryptophan. Accessed 23 Mar. 2023.

Medical Definition

L-tryptophan

noun
L-tryp·​to·​phan ˈel-ˈtrip-tə-ˌfan How to pronounce L-tryptophan (audio)
: the levorotatory form of tryptophan that is a precursor of serotonin and was formerly used in some health food preparations in the belief that it promoted sleep and relieved depression see eosinophilia-myalgia syndrome
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!


Which Came First?

  • baby chick with a brown egg
  • hot take or cold shoulder?
Spell It

Hear a word and type it out. How many can you get right?

TAKE THE QUIZ
Solve today's spelling word game by finding as many words as you can with using just 7 letters. Longer words score more points.

Can you make 12 words with 7 letters?

PLAY