vexation vs vex

vexation is a noun but vex is not a noun.

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

vexation (noun)	vex (noun)
the act of troubling or annoying someone
something or someone that causes anxiety; a source of unhappiness
anger produced by some annoying irritation
the psychological state of being irritated or annoyed

vexation (verb)	vex (verb)
	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