1430, probably aphetic of O.Fr. dial.
enchassement "window frame," from
en- "in," prefix forming verbs, +
casse "case, frame" (see
case (2)) +
-ment. Or possibly from Anglo-L.
cassementum, from
casse. The Irish surname is originally
Mc Casmonde (attested from 1429), from
Mac Asmundr, from Ir.
mac "son of" + O.N.
Asmundr "god protector."
[keys-muh
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