Source : Webster's Revised Unabridged Dictionary (1913)

Philter \Phil"ter\, v. t. [imp. & p. p. {Philtered}; p. pr. &
   vb. n. {Philtering}.]
   1. To impregnate or mix with a love potion; as, to philter a
      draught.

   2. To charm to love; to excite to love or sexual desire by a
      potion. --Gov. of Tongue.