also: グノモン
noun
gnomon; stationary arm of a sundial
Technical term for the part of a sundial that casts a shadow. Also used in geometry for the shape that remains after removing a similar shape from a corner.
See also: ノモン投影 (ノモンとうえい)
日時計のノモンが影を落としている。
The gnomon of the sundial is casting a shadow.
ノモン投影という技法がある。
There is a technique called gnomon projection.