cooed; cooing; coos
Definition of coo
(Entry 1 of 2)
1
: to make the low soft cry of a dove or pigeon or a similar sound
The baby cooed quietly in her crib.
2
: to talk fondly, amorously, or appreciatively
The family cooed over the baby pictures.
COO
abbreviationDefinition of COO (Entry 2 of 2)
chief operating officer
Test Your Vocabulary
Which Word Does Not Belong?
-
- Which of these words does not mean "nonsense"?

Test your vocabulary with our 10-question quiz!
TAKE THE QUIZ
A daily challenge for crossword fanatics.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridged
Share coo
Time Traveler for coo
The first known use of coo was in 1577
See more words from the same year