\Cal"car\, n. [L. calcaria lime kiln, fr. calx, calcis,
lime. See {Calx}.] (Glass manuf.)
A kind of oven, or reverberatory furnace, used for the
calcination of sand and potash, and converting them into
frit. --Ure.

\Cal"car\, n.; L. pl. {Calcaria}. [L., a spur, as worn on
the heel, also the spur of a cock, fr. calx, calcis, the
heel.]
1. (Bot.) A hollow tube or spur at the base of a petal or
   corolla.
2. (Zo["o]l.) A slender bony process from the ankle joint of
   bats, which helps to support the posterior part of the
   web, in flight.
3. (Anat.)
   (a) A spur, or spurlike prominence.
   (b) A curved ridge in the floor of the leteral ventricle
       of the brain; the calcar avis, hippocampus minor, or
       ergot.