The Collaborative International Dictionary of English v.0.48:

Aphrodisiac \Aph`ro*dis"i*ac\, Aphrodisiacal
\Aph`ro*di*si"a*cal\, a. [Gr. ? pertaining to sensual love, fr.
   ?. See Aphrodite.]
   Exciting venereal desire; stimulating the desire for sexual
   gratification.
   [1913 Webster +PJC]

The Collaborative International Dictionary of English v.0.48:

Aphrodisiac \Aph`ro*dis"i*ac\, n.
   That which (as a drug, or some kinds of food) stimulate
   sexual desire.
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

aphrodisiac
    adj 1: exciting sexual desire [syn: aphrodisiac,
           aphrodisiacal, sexy] [ant: anaphrodisiac]
    n 1: a drug or other agent that stimulates sexual desire