English
formstone
A genericization from a trade name of the 1940s, FormStone, itself a proprialization from what had previously been a lexical gap compound, form + stone.
The story
A genericization from a trade name of the 1940s, FormStone, itself a proprialization from what had previously been a lexical gap compound, form + stone.
Today it means
noun A plasterlike artificial stone compound made to resemble stone (rock); the stonelike (rocklike) veneer thus produced.
Language periods are conventional ranges, not dates for this word.
Etymograph / formstone