mop vs dry mop

mop and dry mop both are nouns.

Word	Noun	Adjective	Verb	Adverb
mop	Yes	No	Yes	No
dry mop	Yes	No	No	No

As nouns, dry mop is a hyponym of mop; that is, dry mop is a word with a more specific, narrower meaning than mop:

mop: cleaning implement consisting of absorbent material fastened to a handle; for cleaning floors
dry mop: a dry swab for dusting floors

Other hyponyms of mop include dust mop, dustmop, sponge mop.

mop (noun)	dry mop (noun)
cleaning implement consisting of absorbent material fastened to a handle; for cleaning floors	a dry swab for dusting floors

mop (verb)	dry mop (verb)
make a sad face and thrust out one's lower lip
to wash or wipe with or as if with a mop