ambush vs coup de main

ambush and coup de main both are nouns.

Word	Noun	Adjective	Verb	Adverb
ambush	Yes	No	Yes	No
coup de main	Yes	No	No	No

As nouns, coup de main is a hypernym of ambush; that is, coup de main is a word with a broader meaning than ambush:

ambush: the act of concealing yourself and lying in wait to attack by surprise
coup de main: an attack without warning

Other hypernyms of ambush include surprise attack.

ambush (noun)	coup de main (noun)
the act of concealing yourself and lying in wait to attack by surprise	an attack without warning

ambush (verb)	coup de main (verb)
wait in hiding to attack
hunt (quarry) by stalking and ambushing