凹槽
āo​cáo

groove

凹 āo concave

Pictograph of a concavity. Opposite of 凸.

Historical Pronunciations

Old Chinese
Zhengzhangqriːw
qriːb

Sources

Readings & variants
Unicode
Historical pronunciations
Zhengzhang Shangfang

槽 cáo trough

Phonosemantic compound. 木 represents the meaning and 曹 represents the sound.

Components

木
木 Meaning component
mù tree
曹
曹 Sound component
cáo plaintiff and defendant

Character Evolution

Seal form
Seal Shuowen ~100 AD
Regular Modern

Historical Pronunciations

Old Chinese
Zhengzhangʔsluː
zluː

說文解字

畜獸之食器。从木曹聲。

Sources

Readings & variants
Unicode
Historical pronunciations
Zhengzhang Shangfang
Historical images
Academia Sinica
Etymology
Shuowen Jiezi (說文解字)