thresher vs threshing machine

thresher and threshing machine both are nouns.

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

As nouns, thresher and threshing machine are synonyms defined as:

thresher and threshing machine: a farm machine for separating seeds or grain from the husks and straw

Other synonyms of thresher include thrasher.

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