1. To get bent was an expression meaning to get screwed, perhaps imitative of the angle of insertion. Frequently used as an insult equivalent to "Screw you!".

2. It also means to get drunk or stoned, but in this sense it is not used as an insult.

3. It also means to suffer from accelerated expansion of compressed nitrogen and other gases in muscle fibers and body tissue, as a result of ascending too rapidly from a dive below a couple of atmospheres, roughly. Derived from "getting the bends" because the traditional form of the disease (decompression sickness) causes bubbles in the joints, and the afflicted diver is constantly bending his arms and legs to ease the discomfort.

A