"irregular form," especially in mineralogy, 1838, earlier in German and French, from pseudo- "false, deceptive" + Greek morphē "form," a word of uncertain etymology. Related: Pseudomorphic.
manganese garnet, 1853, earlier spessartine (1837), from French spessartine (1832), from Spessart, district in Bavaria where it is found.
Common garnet generally contains manganese as a component ; which is observable in the colour of the globule that results from melting it with soda. One variety, which contains no lime, has been called spessartine, from its locality, Spessart. ["Conversations on Mineralogy," 1837]
1926, proprietary name of a type of fiberboard, by Mason Fibre Company, Laurel, Mississippi, U.S., and named for William H. Mason (1877-1940), protege of Edison, who patented the process of making it. Earlier (1840) as a word in mineralogy for a type of chloritoid; the name honors Owen Mason of Providence, R.I., a collector who first brought the mineral to the attention of geologists.
1805, in geology and mineralogy, "tendency (of rocks or gems) to break cleanly along natural fissures," from cleave (v.1) + -age. General meaning "action or state of cleaving or being cleft" is from 1867.
The sense of "cleft between a woman's breasts in low-cut clothing" is first recorded 1946, defined in a "Time" magazine article [Aug. 5] as the "Johnston Office trade term for the shadowed depression dividing an actress' bosom into two distinct sections;" traditionally first used in this sense by U.S. publicist Joseph I. Breen (1888-1965), head of the Production Code Administration (replaced 1945 by Eric Johnston), enforcers of Hollywood self-censorship, in reference to Jane Russell's costumes and poses in "The Outlaw."
