ruffian vs plug-ugly

ruffian and plug-ugly both are nouns.

Word	Noun	Adjective	Verb	Adverb
ruffian	Yes	No	No	No
plug-ugly	Yes	No	No	No

As nouns, plug-ugly is a hyponym of ruffian; that is, plug-ugly is a word with a more specific, narrower meaning than ruffian:

Other hyponyms of ruffian include bullyboy, muscle, muscleman, skin, skinhead, tough guy.

ruffian (noun)	plug-ugly (noun)
a cruel and brutal fellow	someone who bullies weaker people