gang-rape vs assault

gang-rape is not a noun while assault is a noun.

Word	Noun	Adjective	Verb	Adverb
gang-rape	No	No	Yes	No
assault	Yes	No	Yes	No

As verbs, assault is a hypernym of gang-rape; that is, assault is a word with a broader meaning than gang-rape:

Other hypernyms of gang-rape include dishonor, dishonour, outrage, rape, ravish, violate.

gang-rape (noun)	assault (noun)
	close fighting during the culmination of a military attack
	a threatened or attempted physical attack by someone who appears to be able to cause bodily harm if not stopped
	the crime of forcing a person to submit to sexual intercourse against his or her will

gang-rape (verb)	assault (verb)
rape (someone) successively with several attackers	attack in speech or writing
	attack someone physically or emotionally
	force (someone) to have sex against their will