San
三
The number three in Japanese.
mitsu as well... but what does this have to do with Go? San-San may be what you're looking for.
Zarlan: Minor correction: mittsu is spelled like this: 三つ
EdwardHammerbeck: Yes, San-San was where I started. It referred to San and had a dead link so I plugged the hole.
Bob MCGuigan: This page has some minor relevance to go because old Japanese (and Chinese?) books use traditional numerals like this in go diagrams and on the sides of the board for coordinates.