miller vs moth

miller and moth both are nouns.

Word	Noun	Adjective	Verb	Adverb
miller	Yes	No	No	No
moth	Yes	No	No	No

As nouns, moth is a hypernym of miller; that is, moth is a word with a broader meaning than miller:

miller: any of various moths that have powdery wings
moth: typically crepuscular or nocturnal insect having a stout body and feathery or hairlike antennae

miller (noun)	moth (noun)
any of various moths that have powdery wings	typically crepuscular or nocturnal insect having a stout body and feathery or hairlike antennae
machine tool in which metal that is secured to a carriage is fed against rotating cutters that shape it
someone who works in a mill (especially a grain mill)