Lock

1. A fastener fitted to a door or drawer to keep it firmly closed. We keep our doors locked.
2. A strand or cluster of hair. She saved a lock of her baby's hair.
3. A secure hold or grip. The company has a lock on that part of the market.
4. To fix in place so that movement or escape is impossible The ship was locked in the ice through the winter.
5. To bind in close struggle or battle, The two dogs were locked in combat.