public debate vs speechmaking

public debate and speechmaking both are nouns.

Word	Noun	Adjective	Verb	Adverb
public debate	Yes	No	No	No
speechmaking	Yes	No	No	No

As nouns, speechmaking is a hypernym of public debate; that is, speechmaking is a word with a broader meaning than public debate:

public debate: the formal presentation of a stated proposition and the opposition to it (usually followed by a vote)
speechmaking: delivering an address to a public audience

Other hypernyms of public debate include oral presentation, public speaking, speaking.

public debate (noun)	speechmaking (noun)
the formal presentation of a stated proposition and the opposition to it (usually followed by a vote)	delivering an address to a public audience