Primary sense: A large residential building or compound that is fortified and contains many defences; in previous ages often inhabited by a nobleman or king. Also, a house or mansion with some of the architectural features of medieval castles.
Grammar: castle is listed as name, noun, verb, slang.
Usage evidence: What you are saying is nothing but building a castle in the air.
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Definitions
Noun
1
A large residential building or compound that is fortified and contains many defences; in previous ages often inhabited by a nobleman or king. Also, a house or mansion with some of the architectural features of medieval castles.
2
interchanging the positions of the king and a rookwordnet
3
An instance of castling.
4
a large building formerly occupied by a ruler and fortified against attackwordnet
5
A rook; a chess piece shaped like a castle tower.informal
Show 7 more definitions
6
(chess) the piece that can move any number of unoccupied squares in a direction parallel to the sides of the chessboardwordnet
7
A defense structure in shogi formed by defensive pieces surrounding the king.
8
a large and stately mansionwordnet
9
A close helmet.obsolete
"The castle was perhaps a figurative name for a close headpiece deduced from its enclosing and defending the head, as a castle did the whole body; or a corruption from the Old French word casquetel, a small or light helmet."
10
Any strong, imposing, and stately palace or mansion.dated
11
A small tower, as on a ship, or an elephant's back.dated
12
The wicket.colloquial
"Nay, he was quite an adept, and was very effective as a change bowler, for in no time he demolished the castle of any batsman."
Verb
1
To house or keep in a castle.transitive
"...to encastle, to Castle."
2
move the king two squares toward a rook and in the same move the rook to the square next past the kingwordnet
3
To protect or separate in a similar way.figuratively, transitive
"Castle me in the armes of thy everlasting strength."
4
To make into a castle: to build in the form of a castle or add (real or imitation) battlements to an existing building.obsolete
5
To move the king 2 squares right or left and, in the same turn, the nearest rook to the far side of the king. The move now has special rules: the king cannot be in, go through, or end in check; the squares between the king and rook must be vacant; and neither piece may have been moved before castling.intransitive, usually
"He [i.e., the king] may change (or Castle) with this Rooke, that is, he may goe two draughts at once towards this Rooke... causing the Rooke to stand next to him on either side."
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6
To create a similar defensive position in Japanese chess through several moves.intransitive, usually
7
To bowl a batsman with a full-length ball or yorker such that the stumps are knocked over.
"And the 23-year-old brought the crowd to their feet when he castled Gayle's stumps, signalling the direction of the pavilion to his friend for good measure."
Proper Noun
1
A surname transferred from the common noun referring to someone who lived in or worked in a castlecountable
2
Castle class, a class of steam locomotives used on the GWRUK, countable, uncountable
3
The first part of the name of certain nuclear tests by the US: Castle Bravo, Castle Romeo, Castle Yankee etc. See Operation Castle.countable, uncountable
4
University College, Durham, a constituent college located in Durham CastleUK, countable, uncountable
5
A place name:; A hamlet in Bowerchalke parish, south-west Wiltshire, England (OS grid ref SU0122).countable, uncountable
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6
A place name:; A community (without a council) in Cardiff, Wales; it includes Cardiff Castle.countable, uncountable
7
A place name:; A community (without a council) in Swansea, Wales; it includes Swansea Castle.countable, uncountable
8
A place name:; A town in Okfuskee County, Oklahoma, United States, derived from the surname.countable, uncountable
"What you are saying is nothing but building a castle in the air."
Common questions
What does "castle" mean?
A large residential building or compound that is fortified and contains many defences; in previous ages often inhabited by a nobleman or king. Also, a house or mansion with some of the architectural features of medieval castles.
What is a synonym for "castle"?
Common synonyms include: acropolis, activate, bastion, beachhead, bishop, blockhouse.
How do you use "castle" in a sentence?
What you are saying is nothing but building a castle in the air.
How do you pronounce "castle"?
Pronounced /ˈkɑːsəl/.
Etymology
Etymology 1
From Middle English castle, castel, from late Old English castel, castell (“a town, village”), borrowed from Late Latin castellum (“small camp, fort”), diminutive of Latin castrum (“camp, fort, citadel, stronghold”). Doublet of cashel, castell, castellum, and château.
Parallel borrowings (from Late Latin or Old French) are Scots castel, castell (“castle”), West Frisian kastiel (“castle”), Dutch kasteel (“castle”), German Kastell (“castle”), Danish kastel (“citadel”), Swedish kastell (“citadel”), Icelandic kastali (“castle”), Welsh castell.
The late Old English word was borrowed from biblical Latin castellum which has been translated as town or village. With the sense of castle, from Anglo-Norman/Old Northern French castel (“castle”), itself from Late Latin castellum (“small camp, fort”) (compare modern French château from Old French chastel). If Latin castrum (“camp, fort, citadel, stronghold”) is from Proto-Indo-European *kat- (“hut, shed”), Latin casa (“cottage, hut”) is related. Possibly related also to Gothic 𐌷𐌴𐌸𐌾𐍉 (hēþjō, “chamber”), Old English heaþor (“restraint, confinement, enclosure, prison”). See also casino, cassock.