mine vs floating mine

mine and floating mine both are nouns.

Word	Noun	Adjective	Verb	Adverb
mine	Yes	No	Yes	No
floating mine	Yes	No	No	No

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

mine: explosive device that explodes on contact; designed to destroy vehicles or ships or to kill or maim personnel
floating mine: an explosive mine designed to destroy ships that bump into it

Other hyponyms of mine include marine mine, booby trap, ground-emplaced mine, land mine.

mine (noun)	floating mine (noun)
explosive device that explodes on contact; designed to destroy vehicles or ships or to kill or maim personnel	an explosive mine designed to destroy ships that bump into it
excavation in the earth from which ores and minerals are extracted

mine (verb)	floating mine (verb)
lay mines
get from the earth by excavation