noun
ceiling boards; ceiling panels
Refers to the boards or panels that make up a ceiling, often in traditional Japanese architecture.
古い家の天井板がきしんでいる。
The ceiling boards in the old house are creaking.
天井 means 'ceiling' in general, while 天井板 specifically refers to the boards or panels that form the ceiling.
Compound of 天井 (てんじょう, 'ceiling') and 板 (いた, 'board').