bullyboy vs yobbo

bullyboy and yobbo both are nouns.

Word	Noun	Adjective	Verb	Adverb
bullyboy	Yes	No	No	No
yobbo	Yes	No	No	No

As nouns, yobbo is a hypernym of bullyboy; that is, yobbo is a word with a broader meaning than bullyboy:

bullyboy: a swaggering tough; usually one acting as an agent of a political faction
yobbo: a cruel and brutal fellow

Other hypernyms of bullyboy include bully, hooligan, roughneck, rowdy, ruffian, tough, yob, yobo.

bullyboy (noun)	yobbo (noun)
a swaggering tough; usually one acting as an agent of a political faction	a cruel and brutal fellow