wash up vs fatigue

wash up is not a noun while fatigue is a noun.

Word	Noun	Adjective	Verb	Adverb
wash up	No	No	Yes	No
fatigue	Yes	No	Yes	No

As verbs, fatigue is a hypernym of wash up; that is, fatigue is a word with a broader meaning than wash up:

Other hypernyms of wash up include fag, fag out, jade, outwear, tire, tire out, wear, wear down, wear out, wear upon, weary.

wash up (noun)	fatigue (noun)
	labor of a nonmilitary kind done by soldiers (cleaning or digging or draining or so on)
	(always used with a modifier) boredom resulting from overexposure to something
	temporary loss of strength and energy resulting from hard physical or mental work
	used of materials (especially metals) in a weakened state caused by long stress

wash up (verb)	fatigue (verb)
wash one's face and hands	exhaust or get tired through overuse or great strain or stress
wear out completely	lose interest or become bored with something or somebody
be carried somewhere by water or as if by water
wash dishes
carry somewhere (of water or current or waves)