Yes, re is a Scrabble word!
...and is worth 2 points in Scrabble, and 2 points in Words with Friends
re
Noun
1. A rare heavy polyvalent metallic element that resembles manganese chemically and is used in some alloys; is obtained as a by-product in refining molybdenum
2. Ancient Egyptian sun god with the head of a hawk; a universal creator; he merged with the god Amen as Amen-Ra to become the king of the gods
3. The syllable naming the second (supertonic) note of any major scale in solmization
What Scrabble words can I make with the letters in re?
2 Letter Words