bath linen vs washcloth

bath linen and washcloth both are nouns.

Word	Noun	Adjective	Verb	Adverb
bath linen	Yes	No	No	No
washcloth	Yes	No	No	No

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

bath linen: linens for use in the bathroom
washcloth: bath linen consisting of a piece of cloth used to wash the face and body

Other hyponyms of bath linen include bath mat, bath towel, face cloth, flannel, washrag.

bath linen (noun)	washcloth (noun)
linens for use in the bathroom	bath linen consisting of a piece of cloth used to wash the face and body