A crucial or decisive point or situation; a turning point.
An unstable situation, in political, social, economic or military affairs, especially one involving an impending abrupt change.
A sudden change in the course of a disease, usually at which the patient is expected to recover or die.
(psychology) A traumatic or stressful change in a person's life.
(drama) A point in a drama at which a conflict reaches a peak before being resolved.