窿 (lóng): (in 窟窿) hole; cavity

Meanings

袜子上有一个大窟窿。

Wàzi shàng yǒu yíge dà kūlong.

There is a big hole in the sock.

矿工深入矿窿。

Kuànggōng shēnrù kuàng lóng.

The miners went deep into the mine tunnel.

usage

Mostly in 窟窿 (a hole), where the second syllable is unstressed. In mining usage 窿 alone means a tunnel or pit shaft.

radical

穴 xué

cave; hole

The cave radical on top makes the meaning clear at a glance: 窿 is about holes, hollows, and underground passages.

phonetic

隆 lóng

grand; swelling

Supplies the reading lóng directly; it works as the sound element with no bearing on the meaning "hole."

窿 lóng