Word Study
cabochon
CIDE DICTIONARY
cabochon, n. [F.].
A stone of convex form, highly polished, but not faceted; also, the style of cutting itself. Such stones are said to be cut en cabochon. [Webster 1913 Suppl.]
OXFORD DICTIONARY
cabochon, n. a gem polished but not faceted.
Idiom
en cabochon (of a gem) treated in this way.
Etymology
F dimin. of caboche: see CABBAGE
For further exploring for "cabochon" in Webster Dictionary Online