i Register
In some senses, custodian is marked as US. Watch for register when choosing this word.
noun
A person entrusted with the custody or care of something or someone; a caretaker or keeper.
After their parents' death, their aunt became the children's custodian.
The building's custodian could fix nearly anything. The place always looked great!
An administrator.
A gaolkeeper.
A protector or guard.
A janitor; a cleaner.