The Collaborative International Dictionary of English v.0.48:

Smirk \Smirk\, v. i. [imp. & p. p. Smirked; p. pr. & vb. n.
   Smirking.] [OE. smirken, ASS. smercian, smearcian; cf. MHG.
   smieren, smielen, to smile. See Smile, v. i.]
   To smile in an affected or conceited manner; to smile with
   affected complaisance; to simper.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

61 Moby Thesaurus words for "smirking":
   bantering, beaming, beatific, beatified, blessed, blissful, booing,
   capering, catcalling, chaffing, cheerful, chirping, dancing,
   derisive, derisory, fleering, flippant, flushed with joy, fooling,
   gay, glad, glowing, grinning, happy, hissing, hooting, jeering,
   joshing, joyful, joyous, kidding, laughing, leaping, leering,
   mocking, panning, purring, quizzical, radiant, ragging, railing,
   rallying, razzing, ridiculing, roasting, scoffing, singing, smart,
   smart-alecky, smart-ass, smiling, sneering, snickering, sniggering,
   snorting, sparkling, starry-eyed, taunting, teasing, thrice happy,
   twitting