mustache vs handle-bars

mustache and handle-bars both are nouns.

Word	Noun	Adjective	Verb	Adverb
mustache	Yes	No	No	No
handle-bars	Yes	No	No	No

As nouns, handle-bars is a hyponym of mustache; that is, handle-bars is a word with a more specific, narrower meaning than mustache:

mustache: an unshaved growth of hair on the upper lip
handle-bars: a large bushy moustache (with hair growing sometimes down the sides of the mouth)

Other hyponyms of mustache include soup-strainer, toothbrush, moustachio, mustachio, walrus moustache, walrus mustache.

mustache (noun)	handle-bars (noun)
an unshaved growth of hair on the upper lip	a large bushy moustache (with hair growing sometimes down the sides of the mouth)