debate vs oppose

debate is a noun but oppose is not a noun.

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

As verbs, oppose is a hyponym of debate; that is, oppose is a word with a more specific, narrower meaning than debate:

debate (noun)	oppose (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

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