Etymology From Medieval Latin castellātus (“fortified, castellate”) + -ed (forming past participles). Equivalent to the past participle of castellate but attested earlier than other uses of the verb.
1
Castle-like: built or shaped like a castle; usually, specifically, having castellations (crenellations).
Near-synonym: crenellated
...A Castellated mansion...1686, Robert Plot, chapter X, in The Natural History of Stafford-shire, page 448:
2 more examples
Finally he walked slowly into a vast Italian space, with towers and castellated roofs, and a sky the colour of dark blue ink, smooth and consistent.2004, Colm Toibin, The Master, page 2:
Three castellated (with battlements) towers stand sentry here, with one being particularly large. This is said to have been used by Rhodes as a belvedere, and (according to some sources) by railway staff for some time after opening.2020 August 26, Tim Dunn, “Great railway bores of our time!”, in Rail, page 46:
2
Engineering, Natural sciences, Physical sciences Having grooves or recesses on an upper face.
Near-synonym: crenellated
Castellated nuts are used throughout, with split pins.1904, Alexander Bell Filson Young, chapter IV, in The Complete Motorist, page 74:
3
Castled: having or furnished with castles.
...This castellated island...1809, Robert Ker Porter, chapter IV, in Travelling Sketches in Russia & Sweden, volume I, page 30: