crasher vs gatecrasher

crasher and gatecrasher both are nouns.

Word	Noun	Adjective	Verb	Adverb
crasher	Yes	No	No	No
gatecrasher	Yes	No	No	No

As nouns, crasher and gatecrasher are synonyms defined as:

crasher and gatecrasher: someone who gets in (to a party) without an invitation or without paying

Other synonyms of crasher include unwelcome guest.

crasher (noun)	gatecrasher (noun)
someone who gets in (to a party) without an invitation or without paying	someone who gets in (to a party) without an invitation or without paying