Outsize rhymes with:
bitesize, anglicize, bitesize, capsize, circumcise, criticize, deemphasize, downsize, emphasize, exercise, fantasize, full-size, hypothesize, metastasize, midsize, ostracize, overemphasize, politicize, powercise, publicize, reemphasize, romanticize, synthesize
Outsize sounds like:
oates, oaths, oatis, oats, odaiko, oddities, odds, odes, odessa, odetics, odious, odysseus, odyssey, odyssey's, otis, otsego, otsuka, ottawa's, ottaway's, otto's, otts, out's, outage, outages, outdoes, outgo, outguess, outguesses, outhouse, outhouses, outs, outtake, outtakes, outweigh, outweighs, outwits, owades