second messenger

noun

Medical Definition of second messenger

: an intracellular substance (as cyclic AMP) that mediates cell activity by relaying a signal from an extracellular molecule (as of a hormone or neurotransmitter) bound to the cell's surface — compare first messenger

Learn More about second messenger

Cite this Entry

“Second messenger.” The Merriam-Webster.com Medical Dictionary, Merriam-Webster Inc., https://www.merriam-webster.com/medical/second%20messenger. Accessed 23 January 2020.

Comments on second messenger

What made you want to look up second messenger? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

out of the ordinary or unreasonable

Get Word of the Day daily email!

Test Your Vocabulary

Intact Latin Quiz

  • roman tablet
  • What did focus mean in Latin?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Add Diction

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

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