forthrightness vs honestness

forthrightness and honestness both are nouns.

Word	Noun	Adjective	Verb	Adverb
forthrightness	Yes	No	No	No
honestness	Yes	No	No	No

As nouns, honestness is a hypernym of forthrightness; that is, honestness is a word with a broader meaning than forthrightness:

forthrightness: the quality of being honest and straightforward in attitude and speech
honestness: the quality of being honest

Other hypernyms of forthrightness include honesty.

forthrightness (noun)	honestness (noun)
the quality of being honest and straightforward in attitude and speech	the quality of being honest