The Collaborative International Dictionary of English v.0.48:
Plantar \Plan"tar\, a. [L. plantaris, fr. planta the sole of the foot.] (Anat.) Of or pertaining to the sole of the foot; as, the plantar arteries. [1913 Webster]WordNet (r) 3.0 (2006):
plantar adj 1: relating to or occurring on the undersurface of the foot; "plantar warts can be very painful"