Yes, tug is a Scrabble word!
...and is worth 4 points in Scrabble, and 6 points in Words with Friends
tug
Verb
1. Pull hard
2. Strive and make an effort to reach a goal
3. Tow (a vessel) with a tug
4. Carry with difficulty
5. Move by pulling hard
6. Pull or strain hard at
7. Struggle in opposition
Noun
1. A sudden abrupt pull
2. A powerful small boat designed to pull or push larger ships
What Scrabble words can I make with the letters in tug?
3 Letter Words
2 Letter Words