Yes, tight is a Scrabble word!

Adverb

1. Firmly or closely

2. In an attentive manner

Adjective

1. Closely constrained or constricted or constricting

2. Pulled or drawn tight

3. Set so close together as to be invulnerable to penetration

4. Pressed tightly together

5. (used of persons or behavior) characterized by or indicative of lack of generosity

6. Affected by scarcity and expensive to borrow

7. Of such close construction as to be impermeable

8. Of textiles

9. Securely or solidly fixed in place; rigid

10. (of a contest or contestants) evenly matched

11. Very drunk

12. Exasperatingly difficult to handle or circumvent

13. Demanding strict attention to rules and procedures

14. Packed closely together