Merriam-Webster Collegiate Dictionary - crisis

 noun  (plural crises)  Etymology: Middle English, from Latin, from Greek krisis, literally, decision, from krinein to decide — more at certain  Date: 15th century  1.  a. the turning point for better or worse in an acute disease or fever  b. a paroxysmal attack of pain, distress, or disordered function  c. an emotionally significant event or radical change of status in a person's life a midlife ~  2. the decisive moment (as in a literary plot)  3.  a. an unstable or crucial time or state of affairs in which a decisive change is impending; especially one with the distinct possibility of a highly undesirable outcome a financial ~  b. a situation that has reached a critical phase the environmental ~  Synonyms: see juncture