crenellate

crenellate: crenellate: [19] The 19th century seems a surprisingly late date for English to have acquired a term so closely associated with medieval battlements, but it is a little misleading. For essentially the same word entered the language in the 13th century as kernel. Both come ultimately from late Latin crēna ‘notch’ (probable source also of English cranny [15]). In Vulgar Latin this developed the diminutive form *crenellus, metathesized in medieval Latin as kernellus.
=> cranny