The Collaborative International Dictionary of English v.0.48:

love-potion \love-potion\ n.
   a fabled drink credited with magical power; it can make the
   one who takes it love the one who gave it.

   Syn: philter, philtre, love-philter, love-philtre.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

love-potion
    n 1: a drink credited with magical power; can make the one who
         takes it love the one who gave it [syn: philter,
         philtre, love-potion, love-philter, love-philtre]