crenel

[kren-l] /ˈkrɛn l/
noun
1.
any of the open spaces between the merlons of a battlement.
2.
a crenature.
verb (used with object), creneled, creneling or (especially British) crenelled, crenelling.
3.
to crenelate.
Also, crenelle
[kri-nel] /krɪˈnɛl/ (Show IPA).
Origin
1475-85; earlier creneul, crennel < Middle French, Old French, apparently diminutive of cren notch (attested since the 15th century), Old French cran, of uncertain origin; cf. crenate, cranny
British Dictionary definitions for crenel

crenel

/ˈkrɛnəl/
noun
1.
any of a set of openings formed in the top of a wall or parapet and having slanting sides, as in a battlement
2.
another name for crenation
Word Origin
C15: from Old French, literally: a little notch, from cren notch, from Late Latin crēna
Word Origin and History for crenel
n.

"open space on an embattlement," early 14c., from Old French crenel (12c.), apparently a diminutive of cren "notch" (see cranny).