coucou

/ku.ku/
1.
interjection

informal hello; 'hey' (often playful or familiar, also used like 'peekaboo' with children)

Coucou ! Tu es là ?

Hey! Are you there?

Synonyms:salut, bonjour, cc
2.
nounmasculine

a short/friendly greeting (a quick 'hi', often a message or brief visit)

Je t'ai envoyé un petit coucou sur Instagram.

I sent you a quick hello on Instagram.

Synonyms:salut, bonjour
3.
nounmasculine

the cuckoo (the bird)

Au printemps, on entend le coucou dans la forêt.

In spring you can hear the cuckoo in the woods.

Synonyms:oiseau
coucou - French Definition & Examples