wellhole

Noun

Japanese Meaning

階段を収めるために床に設けられた開口部 / 階段の段外側に残された開放空間

The carpenter measured the wellhole carefully before fitting the new staircase.

大工は新しい階段を取り付ける前に、階段用の床の開口部を慎重に測定した。

Sense（1）

The open space in a floor, to accommodate a staircase.

Sense（2）

The open space left beyond the ends of the steps of a staircase.

well-holes of the stairs and chimney

Sense（3）

A cavity which receives a counterbalancing weight in certain mechanical contrivances, and is adapted also for other purposes.

wellholes

（ plural ）