The Collaborative International Dictionary of English v.0.48:

Piggish \Pig"gish\, a.
   Relating to, or like, a pig; greedy.
   [1913 Webster]

WordNet (r) 3.0 (2006):

piggish
    adj 1: resembling swine; coarsely gluttonous or greedy; "piggish
           table manners"; "the piggy fat-cheeked little boy and his
           porcine pot-bellied father"; "swinish slavering over
           food" [syn: hoggish, piggish, piggy, porcine,
           swinish]

Moby Thesaurus II by Grady Ward, 1.0:

80 Moby Thesaurus words for "piggish":
   Apician, a hog for, acquisitive, all-devouring, asinine,
   avaricious, avid, beastly, bolting, bottomless, bovid, bovine,
   caprid, caprine, coveting, covetous, cowish, cowlike, cramming,
   crapulent, crapulous, deerlike, devouring, edacious, equestrian,
   equine, esurient, glutting, gluttonizing, gluttonous, goatish,
   goatlike, gobbling, gorging, grabby, grasping, greedy, gulping,
   guttling, guzzling, hircine, hoggish, hoofed, horsy, hyperphagic,
   insatiable, insatiate, intemperate, limitless, mercenary, miserly,
   money-hungry, money-mad, mulish, omnivorous, overgreedy, ovine,
   polyphagic, quenchless, rapacious, ravening, ravenous, ruminant,
   sheepish, sheeplike, slakeless, sordid, stuffing, swinish,
   unappeasable, unappeased, ungulate, unquenchable, unsated,
   unsatisfied, unslakeable, unslaked, venal, voracious, wolfing