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]

The Collaborative International Dictionary of English v.0.48:

Smirk \Smirk\, n.
   A forced or affected smile; a simper.
   [1913 Webster]

         The bride, all smirk and blush, had just entered. --Sir
                                                  W. Scott.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Smirk \Smirk\, a.
   Nice,; smart; spruce; affected; simpering. "So smirk, so
   smooth." --Spenser.
   [1913 Webster]

WordNet (r) 3.0 (2006):

smirk
    n 1: a smile expressing smugness or scorn instead of pleasure
    v 1: smile affectedly or derisively [syn: smirk, simper]