In linear algebra, an n-by-n square matrix A is called invertible (also nonsingular or nondegenerate) if there exists an n-by-n square matrix B such that:
AB = BA = I (where I is the Identity Matrix).
Otherwise, in life, it refers to the case where something can be transformed into something else and transformed back.
Randy: Sally is so invertible; real marriage material.
Sandy: I know, nonsingularly so. Put a few drinks in her and you can get her on her back and yet in the morning she still gets up and cooks you breakfast.
Having the guts or balls to put all of your money in one or a few investments knowing you will either lose it all or get paid
That student who put most of his money in Ford must have serious investicles.
Everyone thought I was an idiot for putting most of my money in Ford but I had good information, insight, and investicles to make the move. I got paid for putting most of my money in Ford.