1.
castle tower; keep; main tower of a Japanese castle
The central, tallest tower of a Japanese castle, serving as both a symbol of the lord's power and a final defensive stronghold. A defining feature of Japanese castle architecture.
Usage
Of Japan's many castles, only twelve retain their original wooden 天守閣, known as 現存天守. The most famous include 姫路城, 松本城, and 犬山城. Many others have been rebuilt in modern materials.
The shorter form 天守 is used interchangeably in many contexts, though 天守閣 is more common in everyday speech.