oppose vs debate

oppose is not a noun while debate is a noun.

Word	Noun	Adjective	Verb	Adverb
oppose	No	No	Yes	No
debate	Yes	No	Yes	No

As verbs, debate is a hypernym of oppose; that is, debate is a word with a broader meaning than oppose:

Other hypernyms of oppose include argue, contend, fence.

oppose (noun)	debate (noun)
	the formal presentation of a stated proposition and the opposition to it (usually followed by a vote)
	a discussion in which reasons are advanced for and against some proposition or proposal

oppose (verb)	debate (verb)
be resistant to	argue with one another
be against; express opposition to	discuss the pros and cons of an issue
set into opposition or rivalry	have an argument about something
fight against or resist strongly	think about carefully; weigh
act against or in opposition to
contrast with equal weight or force