calx

[kalks] /kælks/
noun, plural calxes, calces
[kal-seez] /ˈkæl siz/ (Show IPA)
1.
the oxide or ashy substance that remains after metals, minerals, etc., have been thoroughly roasted or burned.
2.
lime1 (def 1).
Origin
1350-1400; late Middle English < Latin: lime; replacing Middle English cals < Old French < Latin
British Dictionary definitions for calx

calx

/kælks/
noun (pl) calxes, calces (ˈkælsiːz)
1.
the powdery metallic oxide formed when an ore or mineral is roasted
2.
another name for calcium oxide
3.
(anatomy) the heel
Word Origin
C15: from Latin: lime, from Greek khalix pebble
calx in Medicine

calx (kālks)
n. pl. calx·es or cal·ces (kāl'sēz')

  1. The crumbly residue left after a mineral or metal has been calcined or roasted.

  2. The posterior rounded extremity of the foot; the heel.