The Collaborative International Dictionary of English v.0.48:

Lascivious \Las*civ"i*ous\ (l[a^]s*s[i^]v"[i^]*[u^]s), a. [L.
   lascivia wantonness, fr. lascivus wanton; cf. Gr. la`stauros
   lecherous, lh^n to wish, Skr. lash to desire.]
   1. Wanton; lewd; lustful; as, lascivious men; lascivious
      desires. --Milton.
      [1913 Webster]

   2. Tending to produce voluptuous or lewd emotions.
      [1913 Webster]

            He capers nimbly in a lady's chamber
            To the lascivious pleasing of a lute. --Shak.
      -- Las*civ"i*ous*ly, adv. -- Las*civ"i*ous*ness, n.
      [1913 Webster]

WordNet (r) 3.0 (2006):

lascivious
    adj 1: driven by lust; preoccupied with or exhibiting lustful
           desires; "libidinous orgies" [syn: lascivious, lewd,
           libidinous, lustful]