Definitions of certain:
- adjective: exercising or taking care great enough to bring assurance
Example: "Be certain to disconnect the iron when you are through"
- adjective: certain to occur; destined or inevitable
Example: "He was certain to fail"
- adjective: capable of being depended on
Example: "A quick and certain remedy"
- adjective: established irrevocably
- name: A surname (very rare: popularity rank in the U.S.: #20995)