Yes, tic is a Scrabble word!
...and is worth 5 points in Scrabble, and 6 points in Words with Friends
tic
Noun
1. A local and habitual twitching especially in the face
What Scrabble words can I make with the letters in tic?
2 Letter Words
Noun
1. A local and habitual twitching especially in the face
2 Letter Words