Synonyms for Yahoo:

n.

creep, know-all, yob, public nuisance, vermin, loudmouth, horror, (the) scum of the earth, public enemy number one. you beauty, boor, churl, (ay) caramba, chuff, OOH, great, philistine, good, vulgarian, barbarian, by gum, this is the life, it's a pleasure to do something. barbarian (noun)
savage, beast, boor, brute.
savage (noun)
brute, barbarian, beast, boor.
yahoo (noun)
rube, hick, bumpkin, hayseed, yokel, chawbacon.

Other synonyms:

chuff, OOH. philistine, vulgarian. churl. barbarian. lout
boor.
Other relevant words:
great, creep, barbarian, vermin, loudmouth, yob, good, boor, know-all, savage, vulgarian, horror, beast, churl, chuff, brute, OOH, philistine.