矩
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.