Yes, lit is a Scrabble word!
...and is worth 3 points in Scrabble, and 4 points in Words with Friends
lit
Verb
1. Make lighter or brighter
2. Begin to smoke
3. To come to rest, settle
4. Cause to start burning; subject to fire or great heat
5. Fall to somebody by assignment or lot
6. Alight from (a horse)
Adjective
1. Provided with artificial light
2. Set afire or burning
Noun
1. The humanistic study of a body of literature
What Scrabble words can I make with the letters in lit?
3 Letter Words
2 Letter Words