Yes, lose is a Scrabble word!

Verb

1. Fail to keep or to maintain; cease to have, either physically or in an abstract sense

2. Fail to win

3. Suffer the loss of a person through death or removal

4. Place (something) where one cannot find it again

5. Miss from one's possessions; lose sight of

6. Allow to go out of sight

7. Fail to make money in a business; make a loss or fail to profit

8. Fail to get or obtain

9. Retreat

10. Fail to perceive or to catch with the senses or the mind

11. Be set at a disadvantage