bent over
Legs (or at least thighs) vertical, with the torso bent over horizontally and ass sticking out.
As a rule of thumb, if the character is bent far enough forward that they need to rest their weight on something to avoid falling over, they are bent over, otherwise they are leaning forward.
Examples
See also
The following tags are aliased to this tag: bend_over, bending_over, and bent-over (learn more).

