calcar

from The Century Dictionary.

• noun In entomology, one of the spines at the tips of the tibiæ of certain insects, especially the Hymenoptera. Also called spur.
• noun In glass-works, an oven or furnace for calcining the materials of frit, prior to melting. Also called fritting-furnace.
• noun In metallurgy, an annealing-arch or -oven.
• noun In botany, a spur; a hollow projection from the base of a petal or sepal; the nectary (nectarium) of Linnæus.
• noun In anatomy, a projection into the posterior horn of the lateral ventricle of the brain of man and some other mammals; the calcar avis or hippocampus minor.
• noun In ornithology, a spur.
• noun In Rotifera, a spur-like setigerous process more or less closely attached to the single ganglion of these animals, near the trochal disk.
• noun In Chiroptera, a slender elongated bone or cartilage upon the inner side of the ankle-joint, assisting in the support of the patagium.
• noun [capitalized] [NL.] In entomology, a genus of atracheliate beetles, of the family Tenebrionidæ.
• noun [capitalized] [NL.] In conchology, a genus of mollusks.
• noun The spur forming part of any ceremonial costume.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Glass manuf.) A kind of oven, or reverberatory furnace, used for the calcination of sand and potash, and converting them into frit.
• noun (Bot.) A hollow tube or spur at the base of a petal or corolla.
• noun (Zoöl.) A slender bony process from the ankle joint of bats, which helps to support the posterior part of the web, in flight.
• noun A spur, or spurlike prominence.
• noun A curved ridge in the floor of the leteral ventricle of the brain; the calcar avis, hippocampus minor, or ergot.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A small oven or furnace.
• noun botany, anatomy A spur-like projection.