fluff vs boner

fluff and boner both are nouns.

Word	Noun	Adjective	Verb	Adverb
fluff	Yes	No	Yes	No
boner	Yes	No	No	No

As nouns, boner is a hypernym of fluff; that is, boner is a word with a broader meaning than fluff:

Other hypernyms of fluff include bloomer, blooper, blunder, boo-boo, botch, bungle, flub, foul-up, fuckup, pratfall.

fluff (noun)	boner (noun)
a blunder (especially an actor's forgetting the lines)	an embarrassing mistake
something of little value or significance
any light downy material

fluff (verb)	boner (verb)
ruffle (one's hair) by combing the ends towards the scalp, for a full effect
erect or fluff up
make a mess of, destroy or ruin