thresher vs farm machine

thresher and farm machine both are nouns.

Word	Noun	Adjective	Verb	Adverb
thresher	Yes	No	No	No
farm machine	Yes	No	No	No

As nouns, farm machine is a hypernym of thresher; that is, farm machine is a word with a broader meaning than thresher:

thresher: a farm machine for separating seeds or grain from the husks and straw
farm machine: a machine used in farming

thresher (noun)	farm machine (noun)
large pelagic shark of warm seas with a whiplike tail used to round up small fish on which to feed	a machine used in farming
a farm machine for separating seeds or grain from the husks and straw