researcher vs boffin

researcher and boffin both are nouns.

Word	Noun	Adjective	Verb	Adverb
researcher	Yes	No	No	No
boffin	Yes	No	No	No

As nouns, boffin is a hyponym of researcher; that is, boffin is a word with a more specific, narrower meaning than researcher:

researcher: a scientist who devotes himself to doing research
boffin: (British slang) a scientist or technician engaged in military research

Other hyponyms of researcher include experimenter, fieldworker, post doc, postdoc.

researcher (noun)	boffin (noun)
a scientist who devotes himself to doing research	(British slang) a scientist or technician engaged in military research