You searched for: “loch
loch, lock, lock
loch (LAHKH, LAHK) (noun)
A lake or an arm of the sea similar to a fjord: This is the famous loch where a monster is alleged to be living.
lock (LAHK) (noun)
1. A device operated by a key, combination, or keycard and used, as on a entrance gate, for holding, closing, or securing something: When Millie bought her condominium, she changed the lock on the front door.
2. A gate which closes off a section of a waterway, such as a canal, in which vessels in transit are raised or lowered by raising or lowering the water level of that part: After Shelby and Fred paid their fees, the master of the lock allowed them to move their boat into the lock and raised them to the next level of the river.
3. A ringlet or small bunch of hair: Craig carried a lock of Estella's hair to remind himself how much he missed her.
lock (LAHK) (verb)
To secure or to fix something in place, typically using a key: Alan will lock the gate after the last person goes home.

The controller of the lock used an electric key to unlock the lock between the river and the loch.