barbican

plural barbicans · alternative barbacan

1. A tower at the entrance to a castle or fortified town.

   Near-synonym: guardhouse

   1 more example

   The stone part of the drawbridge with its barbican and the bartizans of the gatehouse are in good repair. […] There was a large hidden trapdoor in the floor of the barbican, which would let them into the moat after all.

   1958, T[erence] H[anbury] White, chapter V, in The Once and Future King, New York, N.Y.: G. P. Putnam's Sons, →ISBN, book I (The Sword in the Stone)

   Synonyms: guardhouse

2. A fortress at the end of a bridge.
3. An opening in the wall of a fortress through which the guns are levelled; a narrow loophole through which arrows and other missiles may be shot.

   Two shafts of soft daylight fell across the flagged floor from the high barbacans.

   1922 February 2, James Joyce, “[Episode 11]”, in Ulysses, Paris: Shakespeare and Company […], →OCLC

   Synonyms: balistraria, arrowslit, arrow slit, arrow-hole, loophole

4. A temporary wooden tower built for defensive purposes.

1. A neighbourhood in Plymouth, Devon, England (OS grid ref SX4854).
2. A neighbourhood and residential estate in the City of London, Greater London, England (OS grid ref TQ3281)