To fear or doubt that something may fail or be unsafe; to have misgivings or be apprehensive about something (used as 'to be feared' or 'to fear that ~').
専門家たちはその計画の実現性を危ぶんでいる。
Experts are doubtful about the feasibility of the plan.
台風の接近で登山の安全が危ぶまれたため、予定は中止になった。
Because the approaching typhoon made the climb unsafe, the plan was canceled.
出場選手のコンディションを観客も危ぶんでいた。
Spectators were also concerned about the competitors' condition.