WordNet (r) 3.0 (2006):

outsize
    adj 1: larger than normal for its kind [syn: outsize,
           outsized, oversize, oversized]
    n 1: an unusual garment size (especially one that is very large)

Moby Thesaurus II by Grady Ward, 1.0:

49 Moby Thesaurus words for "outsize":
   Gargantuan, amplitudinous, astronomical, awesome, boundless, bulky,
   colossal, cosmic, enormous, extensive, galactic, giantism,
   gigantic, gigantism, huge, hypertrophy, immeasurable, immense,
   infinite, king-size, large, mammoth, massive, massy, monster,
   monstrous, monumental, mountainous, outsized, overbig,
   overdeveloped, overdevelopment, overfed, overgrown, overgrowth,
   overlarge, overlargeness, oversized, overweight, prodigious,
   sizable, spacious, stupendous, titanic, too big, tremendous, vast,
   voluminous, weighty