hassle vs vex

hassle is a noun but vex is not a noun.

Word	Noun	Adjective	Verb	Adverb
hassle	Yes	No	Yes	No
vex	No	No	Yes	No

As verbs, vex is a hypernym of hassle; that is, vex is a word with a broader meaning than hassle:

Other hypernyms of hassle include annoy, bother, chafe, devil, get at, get to, gravel, irritate, nark, nettle, rag, rile.

hassle (noun)	vex (noun)
disorderly fighting
an angry disturbance

hassle (verb)	vex (verb)
annoy continually or chronically	be a mystery or bewildering to
	subject to prolonged examination, discussion, or deliberation
	change the arrangement or position of
	cause annoyance in; disturb, especially by minor irritations
	disturb the peace of mind of; afflict with mental agitation or distress