trencherman vs feeder

trencherman and feeder both are nouns.

Word	Noun	Adjective	Verb	Adverb
trencherman	Yes	No	No	No
feeder	Yes	No	No	No

As nouns, feeder is a hypernym of trencherman; that is, feeder is a word with a broader meaning than trencherman:

Other hypernyms of trencherman include eater.

trencherman (noun)	feeder (noun)
a person who is devoted to eating and drinking to excess	an animal being fattened or suitable for fattening
	an animal that feeds on a particular source of food
	a machine that automatically provides a supply of some material
	an outdoor device that supplies food for wild birds
	a branch that flows into the main stream
	someone who consumes food for nourishment