Calcar n. : A kind of oven, or reverberatory furnace, used for the calcination of sand and potash, and converting them into frit.

Calcar n. : A hollow tube or spur at the base of a petal or corolla.

Calcar n. : A slender bony process from the ankle joint of bats, which helps to support the posterior part of the web, in flight.

Calcar n. : A spur, or spurlike prominence.

Calcar n. : A curved ridge in the floor of the leteral ventricle of the brain; the calcar avis, hippocampus minor, or ergot.

Example:
where is Calcar located in the hindlimbs of a frog?

Taxonomy
hybrids, California Cars Initiative, hybrid cars, plug-in hybrid, gas guzzlers, campaign, global warming, advanced automotive technology, PHEV, cars, clean cars, CalCars, HEV, pluggable, grid, EVs, News flashes, dozen.

Defination from the web:
Works to spur adoption of efficient, non-polluting automotive technologies, including the Prius+, a modified Toyota Prius with larger batteries that offers the option of plugging in for higher mileage per gallon.