- 1[not before noun] uncertain (about/of something) feeling doubt about something; not sure They're both uncertain about what to do. I'm still uncertain of my feelings for him. opposite certain
- 2likely to change, especially in a negative or unpleasant way Our future looks uncertain. a man of uncertain temper
- 3not definite or decided synonym unclear It is uncertain what his role in the company will be.
- 4not confident synonym hesitant The baby took its first uncertain steps. Idioms
clearly and strongly I told him what I thought of him in no uncertain terms.
Check pronunciation: uncertain