coup de main vs ambush

coup de main and ambush both are nouns.

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

As nouns, ambush is a hyponym of coup de main; that is, ambush is a word with a more specific, narrower meaning than coup de main:

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

Other hyponyms of coup de main include terrorist attack, ambuscade, lying in wait, trap, pre-emptive strike.

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

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