WordNet (r) 3.0 (2006):

bigheaded
    adj 1: (used colloquially) overly conceited or arrogant; "a
           snotty little scion of a degenerate family"-Laurent Le
           Sage; "they're snobs--stuck-up and uppity and
           persnickety" [syn: bigheaded, persnickety, snooty,
           snot-nosed, snotty, stuck-up, too big for one's
           breeches, uppish]