Yes, unit is a Scrabble word!

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