Denshi Jisho — Online Japanese dictionary

ます 1: measuring container; measure;
2: box (seating at a theatre, etc.);
3: square on a grid; cell of a grid
Noun 
とます 18-litre measuring container
Noun 
一斗 いっとます 18-litre measuring container
Noun 

You can also

Look up kanji details for *枡.

Try a Yahoo Jisho search for *枡 .
Try a Goo Jisho search for *枡 .
Try a Google search for *枡 .