locker vs fastening

locker and fastening both are nouns.

Word	Noun	Adjective	Verb	Adverb
locker	Yes	No	No	No
fastening	Yes	No	No	No

As nouns, fastening is a hypernym of locker; that is, fastening is a word with a broader meaning than locker:

Other hypernyms of locker include fastener, fixing, holdfast.

locker (noun)	fastening (noun)
a storage compartment for clothes and valuables; usually it has a lock	the act of fastening things together
a trunk for storing personal possessions; usually kept at the foot of a bed (as in a barracks)	restraint that attaches to something or holds something in place
a fastener that locks or closes