The Collaborative International Dictionary of English v.0.48:
Porcelain \Por"ce*lain\ (277), n. [F. porcelaine, It.
porcellana, orig., the porcelain shell, or Venus shell
(Cypr[ae]a porcellana), from a dim. fr. L. porcus pig,
probably from the resemblance of the shell in shape to a
pig's back. Porcelain was called after this shell, either on
account of its smoothness and whiteness, or because it was
believed to be made from it. See Pork.]
A fine translucent or semitransculent kind of earthenware,
made first in China and Japan, but now also in Europe and
America; -- called also China, or China ware.
Porcelain, by being pure, is apt to break. --Dryden.
Ivory porcelain, porcelain with a surface like ivory,
produced by depolishing. See Depolishing.
Porcelain clay. See under Clay.
Porcelain crab (Zool.), any crab of the genus Porcellana
and allied genera (family Porcellanid[ae]). They have a
smooth, polished carapace.
Porcelain jasper. (Min.) See Porcelanite.
Porcelain printing, the transferring of an impression of an
engraving to porcelain.
Porcelain shell (Zool.), a cowry.