Yes, size is a Scrabble word!
...and is worth 13 points in Scrabble, and 13 points in Words with Friends
size
Verb
1. Cover or stiffen or glaze a porous material with size or sizing (a glutinous substance)
2. Sort according to size
3. Make to a size; bring to a suitable size
Adjective
1. (used in combination) sized
Noun
1. The physical magnitude of something (how big it is)
2. The property resulting from being one of a series of graduated measurements (as of clothing)
3. Any glutinous material used to fill pores in surfaces or to stiffen fabrics
4. The actual state of affairs
5. A large magnitude
What Scrabble words can I make with the letters in size?
3 Letter Words
2 Letter Words