sully vs badmouth

sully and badmouth both are verbs.

Word	Noun	Adjective	Verb	Adverb
sully	No	No	Yes	No
badmouth	No	No	Yes	No

As verbs, badmouth is a hyponym of sully; that is, badmouth is a word with a more specific, narrower meaning than sully:

sully: charge falsely or with malicious intent; attack the good name and reputation of someone
badmouth: speak unfavorably about

Other hyponyms of sully include assassinate, libel, drag through the mud, malign, traduce.

sully (verb)	badmouth (verb)
charge falsely or with malicious intent; attack the good name and reputation of someone	speak unfavorably about
make dirty or spotty, as by exposure to air; also used metaphorically
place under suspicion or cast doubt upon