noun
Traditional Japanese unit of length, about 3.03 cm. Still used in some contexts like carpentry, sewing, and idiomatic expressions.
この板の厚さは一寸です。
This board is one sun thick.
noun
Refers to length or measurement in a general sense, often used in set phrases or when talking about dimensions.
寸法を測ってください。
Please measure the dimensions.
noun
shortness; tininess
Used figuratively to indicate a very small amount or shortness, often in negative expressions like 寸が足りない (to be a little short).
See also: 寸が足りない (すんがたりない)
あと一寸のところで電車に乗り遅れた。
I missed the train by a hair's breadth.
The kanji 寸 originally depicted a hand with a mark indicating the pulse point, later used as a unit of length. The reading すん is the Sino-Japanese on'yomi.