Traditional Japanese unit of length, about 3.03 cm. Still used in some contexts like carpentry, sewing, and idiomatic expressions.
This board is one sun thick.
Refers to length or measurement in a general sense, often used in set phrases or when talking about dimensions.
Please measure the dimensions.
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)
I missed the train by a hair's breadth.
This board is three sun thick.
The trousers are a bit too short in the leg.