certainty certainty /ˈsɝːtənti/

noun

1. () The state of being certain  ( certainty )
   the state of being certain
    His certainty reassured the others
   his certainty reassured the others
   
2. () Something that is certain  ( foregone conclusion , sure thing , dead cert [Informal, British] , certainty )
   something that is certain
    His victory is a certainty
   his victory is a certainty