Yes, unit is a Scrabble word!
...and is worth 4 points in Scrabble, and 6 points in Words with Friends
unit
Noun
1. Any division of quantity accepted as a standard of measurement or exchange
2. An individual or group or structure or other entity regarded as a structural or functional constituent of a whole
3. An organization regarded as part of a larger social group
4. A single undivided whole
5. A single undivided natural thing occurring in the composition of something else
6. An assemblage of parts that is regarded as a single entity
What Scrabble words can I make with the letters in unit?
3 Letter Words
2 Letter Words