Yes, taxi is a Scrabble word!
...and is worth 11 points in Scrabble, and 11 points in Words with Friends
taxi
Verb
1. Travel slowly
2. Ride in a taxicab
Noun
1. A car driven by a person whose job is to take passengers where they want to go in exchange for money
What Scrabble words can I make with the letters in taxi?
3 Letter Words
2 Letter Words