crossbencher vs legislator

crossbencher and legislator both are nouns.

Word	Noun	Adjective	Verb	Adverb
crossbencher	Yes	No	No	No
legislator	Yes	No	No	No

As nouns, legislator is a hypernym of crossbencher; that is, legislator is a word with a broader meaning than crossbencher:

crossbencher: a member of the House of Commons who does not vote regularly with either the government or the Opposition
legislator: someone who makes or enacts laws

crossbencher (noun)	legislator (noun)
a member of the House of Commons who does not vote regularly with either the government or the Opposition	someone who makes or enacts laws