1. opposite side; bottom; other side; side hidden from view; undersurface; reverse side
2. rear; back; behind
3. lining; inside
4. in the shadows; behind the scenes; offstage; behind (someone's) back
5. more (to something than meets the eye); hidden side (e.g. of one's personality); unknown circumstances; different side
6. proof
7. opposite (of a prediction, common sense, etc.); contrary
8. inverse (of a hypothesis, etc.)
9. bottom (of an inning); last half (of an inning)