Yes, side is a Scrabble word!

Verb

1. Take sides for or against

Adjective

1. Located on a side

Noun

1. A place within a region identified relative to a center or reference location

2. One of two or more contesting groups

3. Either the left or right half of a body

4. A surface forming part of the outside of an object

5. An extended outer surface of an object

6. An aspect of something (as contrasted with some other implied aspect)

7. A line segment forming part of the perimeter of a plane figure

8. A family line of descent

9. A lengthwise dressed half of an animal's carcass used for food

10. An opinion that is held in opposition to another in an argument or dispute

11. An elevated geological formation

12. (sports) the spin given to a ball by striking it on one side or releasing it with a sharp twist