fishing boat vs dragger

fishing boat and dragger both are nouns.

Word	Noun	Adjective	Verb	Adverb
fishing boat	Yes	No	No	No
dragger	Yes	No	No	No

As nouns, dragger is a hyponym of fishing boat; that is, dragger is a word with a more specific, narrower meaning than fishing boat:

fishing boat: a vessel for fishing; often has a well to keep the catch alive
dragger: a fishing boat that uses a trawl net or dragnet to catch fish

Other hyponyms of fishing boat include trawler.

fishing boat (noun)	dragger (noun)
a vessel for fishing; often has a well to keep the catch alive	a fishing boat that uses a trawl net or dragnet to catch fish
	someone who pulls or tugs or drags in an effort to move something