Yes, lash is a Scrabble word!
...and is worth 7 points in Scrabble, and 7 points in Words with Friends
lash
Verb
1. Beat severely with a whip or rod
2. Lash or flick about sharply
3. Strike as if by whipping
4. Bind with a rope, chain, or cord
Noun
1. Any of the short curved hairs that grow from the edges of the eyelids
2. Leather strip that forms the flexible part of a whip
3. A quick blow delivered with a whip or whiplike object
What Scrabble words can I make with the letters in lash?
3 Letter Words
2 Letter Words