Yes, cramp is a Scrabble word!

Verb

1. Secure with a cramp

2. Prevent the progress or free movement of

3. Affect with or as if with a cramp

4. Suffer from sudden painful contraction of a muscle

Noun

1. A painful and involuntary muscular contraction

2. A clamp for holding pieces of wood together while they are glued

3. A strip of metal with ends bent at right angles; used to hold masonry together