thrasher vs thresher shark

thrasher and thresher shark both are nouns.

Word	Noun	Adjective	Verb	Adverb
thrasher	Yes	No	No	No
thresher shark	Yes	No	No	No

As nouns, thrasher and thresher shark are synonyms defined as:

thrasher and thresher shark: large pelagic shark of warm seas with a whiplike tail used to round up small fish on which to feed

Other synonyms of thrasher include Alopius vulpinus, fox shark, thresher.

thrasher (noun)	thresher shark (noun)
thrush-like American songbird able to mimic other birdsongs	large pelagic shark of warm seas with a whiplike tail used to round up small fish on which to feed
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