Yes, beet is a Scrabble word!
...and is worth 6 points in Scrabble, and 7 points in Words with Friends
beet
Noun
1. Biennial Eurasian plant usually having a swollen edible root; widely cultivated as a food crop
2. Round red root vegetable
What Scrabble words can I make with the letters in beet?
3 Letter Words
2 Letter Words