tsubo

an informal unit of area used in Japan to measure area inside buildings. One tsubo is an area of about 3.3 square meters (3.95 square yards), an area that can be covered neatly by two traditional tatami mats. See tatami, above.
Found on http://www.unc.edu/~rowlett/units/dictT.html

Tsubo

Japanese words つぼ have the following meanings: ...
Found on http://en.wikipedia.org/wiki/Tsubo

Tsubo

A jar
Found on http://www.wafuku.co.uk/glossary.htm
No exact match found