locksmithnoun
A person who makes keys and opens or repairs locks.
keynoun
A small object used to open or lock a door.
locknoun
A piece of metal fitted on a door that keeps it shut until you put the key in it.
llavekey
I left the key inside and the door closed on its own.
chapalock
Do you know if the lock can be opened without the key?
cerrajerolocksmith
I'd better call a locksmith to open the lock.