washup vs shower bath

washup and shower bath both are nouns.

Word	Noun	Adjective	Verb	Adverb
washup	Yes	No	No	No
shower bath	Yes	No	No	No

As nouns, shower bath is a hyponym of washup; that is, shower bath is a word with a more specific, narrower meaning than washup:

washup: the act of washing yourself (or another person)
shower bath: washing yourself by standing upright under water sprayed from a nozzle

Other hyponyms of washup include shower, bath, sponge bath, steam bath, Turkish bath, vapor bath, vapour bath.

washup (noun)	shower bath (noun)
the act of washing yourself (or another person)	washing yourself by standing upright under water sprayed from a nozzle
the act of washing dishes	booth for washing yourself, usually in a bathroom