Webster's Revised Unabridged Dictionary · 1913

Crisis

Crisis (kr?"s?s) , noun

[Latin crisis, Greek {not transcribed}, from {not transcribed} to separate. See Certain.]

1.
The point of time when it is to be decided whether any affair or course of action must go on, or be modified or terminate; the decisive moment; the turning point.
This hour's the very crisis of your fate. — Dryden
The very times of crisis for the fate of the country. — Brougham
2.
(Medicine) That change in a disease which indicates whether the result is to be recovery or death; sometimes, also, a striking change of symptoms attended by an outward manifestation, as by an eruption or sweat.
Till some safe crisis authorize their skill. — Dryden