debate vs bicker

debate and bicker both are nouns.

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

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

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

debate (verb)	bicker (verb)
argue with one another	argue over petty things
discuss the pros and cons of an issue
have an argument about something
think about carefully; weigh