un|cer|tain «uhn SUR tuhn», adjective.
1. not known with certainty; not finally established; in doubt; dubious: »
The election results were still uncertain.
2. not sure; doubtful: »
to be uncertain if a candidate will win. She came so late that she was uncertain of her welcome.
3. likely to change; not to be depended upon; not reliable: »
This dog has an uncertain temper.
7. that may not happen.
–un|cer´tain|ness, noun.
Synonym Study 1, 2 Uncertain, insecure mean not sure in some way or about something. Uncertain implies not knowing definitely or surely about something or not having complete confidence in a thing, person, or oneself, and thus suggests the presence of doubt: »
His plans for the summer are uncertain.
Insecure implies not being protected from or guarded against danger loss, and suggests the presence of fear or anxiety: »Her position at the bank is insecure.
Useful english dictionary. 2012.