break off vs fracture

break off is not a noun while fracture is a noun.

Word	Noun	Adjective	Verb	Adverb
break off	No	No	Yes	No
fracture	Yes	No	Yes	No

As verbs, fracture is a hyponym of break off; that is, fracture is a word with a more specific, narrower meaning than break off:

Other hyponyms of break off include bog, bog down, break up, cut off, disrupt, interrupt.

break off (noun)	fracture (noun)
	the act of cracking something
	(geology) a crack in the earth's crust resulting from the displacement of one side with respect to the other
	breaking of hard tissue such as bone

break off (verb)	fracture (verb)
prevent completion	fracture a bone of
interrupt before its natural or planned end	become fractured
break a small piece off from	violate or abuse
break off (a piece from a whole)	break into pieces
break a piece from a whole	interrupt, break, or destroy