1. a person who takes care of or protects something
2. a person employed to clean and maintain a building

Examples

• The museum custodian carefully protected the ancient artifacts.
• She served as custodian of her grandmother’s estate.
• The school custodian mopped the floors every evening.
• He worked as a custodian at the office building for twenty years.
• The bank acts as custodian of the trust fund.
• The custodian unlocked the classroom doors each morning.
• As custodian of the family records, she preserved important documents.