矩 - Ju3 - Carpenter’s Square

Unfortunately nobody can be told what the 矩陣 is. You have to see it for yourself.

OK, fine, I’ll tell you. 矩陣 - Ju3 Zhen4 - Matrix. But the title of the movie in Chinese is actually 駭客任務 - Hai4 Ke4 Ren4 Wu5 - Hacker Mission. Lame, huh.

And here is an An English-Chinese Dictionary of Mathematical Terms.