To feel apprehensive about the possibility of an unfavorable outcome, often accompanied by a sense of worry or concern regarding future events.

To question the likelihood of achieving a desired result, often reflecting uncertainty about the feasibility or success of a situation.

To be troubled by the thought that a situation may lead to danger or adverse consequences, indicating a deep-seated anxiety about the present or future state of affairs.

To express doubt or skepticism about the realization of something, as in feeling that success or progress may be at risk.