castellation

castellation (countable and uncountable, plural castellations)

1. (uncountable) The act or process of making a building into a castle.
2. (uncountable) The addition of battlements to a building, as for example when a feudal manor house needed fortification against border-raider attacks.
3. (countable) Any of a set of slots or grooves in an object, often machined into a metal part, as for example on a castellated nut.

• crenellation (overlaps synonymously in the architectural sense; coordinate in the machinery sense, whereas the same concept is invoked but the words are used in idiomatically non-interchangeable ways, as with crenellated flashlight bezels but castellated nuts)

• castellate

• licence to crenellate

• allectations