ambuscade vs surprise attack

ambuscade and surprise attack both are nouns.

Word	Noun	Adjective	Verb	Adverb
ambuscade	Yes	No	Yes	No
surprise attack	Yes	No	No	No

As nouns, surprise attack is a hypernym of ambuscade; that is, surprise attack is a word with a broader meaning than ambuscade:

ambuscade: the act of concealing yourself and lying in wait to attack by surprise
surprise attack: an attack without warning

Other hypernyms of ambuscade include coup de main.

ambuscade (noun)	surprise attack (noun)
the act of concealing yourself and lying in wait to attack by surprise	an attack without warning

ambuscade (verb)	surprise attack (verb)
wait in hiding to attack