sex drive

from WordNet (r) 3.0 (2006)

sex drive
    n 1: a physiological need for sexual activity; "testosterone is
         responsible for the male sex drive"

from Moby Thesaurus II by Grady Ward, 1.0

18 Moby Thesaurus words for "sex drive":
      carnality, coldness, flesh, fleshliness, frigidity, impotence,
      libido, love, lovemaking, marriage, potency, sensuality, sexiness,
      sexual instinct, sexual urge, sexualism, sexuality,
      voluptuousness