Jump to:

• castle
  castle

  noun

  a fortified, usually walled residence, as of a prince or noble in feudal times.
• Castle
  Castle

  noun

  Irene (Foote), 1893–1969, born in the U.S., and her husband and partner Vernon (Vernon Castle Blythe ), 1887–1918, born in England, U.S. ballroom dancers.

castle

¹ American  

[kas-uhl, kah-suhl] / ˈkæs əl, ˈkɑ səl /

noun

1. a fortified, usually walled residence, as of a prince or noble in feudal times.

   Synonyms:

   citadel, fortress

2. the chief and strongest part of the fortifications of a medieval city.

3. a strongly fortified, permanently garrisoned stronghold.

4. a large and stately residence, especially one, with high walls and towers, that imitates the form of a medieval castle.

   Synonyms:

   château, palace

5. any place providing security and privacy.

   It may be small, but my home is my castle.

6. Chess. the rook.

---

verb (used with object)

castled, castling

1. to place or enclose in or as in a castle.

2. Chess. to move (the king) in castling.

verb (used without object)

Chess.

castled, castling

1. to move the king two squares horizontally and bring the appropriate rook to the square the king has passed over.

2. (of the king) to be moved in this manner.

Castle ² American  

[kas-uhl, kah-suhl] / ˈkæs əl, ˈkɑ səl /

noun

1. Irene (Foote), 1893–1969, born in the U.S., and her husband and partner Vernon (Vernon Castle Blythe ), 1887–1918, born in England, U.S. ballroom dancers.

---

castle British  

/ ˈkɑːsəl /

noun

1. a fortified building or set of buildings, usually permanently garrisoned, as in medieval Europe

2. any fortified place or structure

3. a large magnificent house, esp when the present or former home of a nobleman or prince

4. the citadel and strongest part of the fortifications of a medieval town

5. chess another name for rook 2

---

verb

1. chess to move (the king) two squares laterally on the first rank and place the nearest rook on the square passed over by the king, either towards the king's side ( castling short ) or the queen's side ( castling long )

Other Word Forms

• castlelike
  adjective
• uncastled
  adjective

Etymology

Origin of castle

before 1000; Middle English, Old English castel < Latin castellum castellum

Explanation

A castle is a huge, grand home where a king or queen might live. Almost all castles are also fortified against attacks by enemy armies. Most castles were built in the Middle Ages by royalty or other nobility. You can still visit many historic castles in Europe, most of them built of stone and including details like towers and guardhouses. You can also call the chess piece known as a "rook" a castle, for its castle-like shape. The word has an Old English root, castel, or "village."

Example Sentences

For Sean Fernando’s wedding at Adare Manor in Ireland last year, New York luxury event planner Marcy Blum helped the groom stage a golf competition on the grounds of the nearly 200-year-old castle landmark-turned-resort.

From The Wall Street Journal • May 19, 2026

On another front, Israel struck at least two villages in southern Lebanon on Wednesday, including one near a 12-century Crusader-era castle, according to AFP images.

From Barron's • May 6, 2026

Researchers identified seven Da Vinci family homes in the village and castle of Vinci, along with two properties once owned by Leonardo himself.

From Science Daily • May 4, 2026

Over two sold-out nights, she turned the 20,000-capacity venue into a magical playground, kitted out like a fairytale castle.

From BBC • May 2, 2026

Soon the royal carriage emerged from the castle gates behind me to parade through The Kingdom and display the new queen.

From "Rump: The (Fairly) True Story of Rumpelstilskin" by Liesl Shurtliff