Yes, locking is a Scrabble word!

Verb

1. Fasten with a lock

2. Keep engaged

3. Become rigid or immoveable

4. Hold in a locking position

5. Become engaged or intermeshed with one another

6. Hold fast (in a certain state)

7. Place in a place where something cannot be removed or someone cannot escape

8. Pass by means through a lock in a waterway

9. Build locks in order to facilitate the navigation of vessels

Noun

1. The act of locking something up to protect it