straits, exigency, emergency, turning point, urgency, necessity, dilemma, puzzle, perplexity, pressure, embarrassment, pinch, juncture, pass, change, contingency, plight, imbroglio, impasse, deadlock, entanglement, predicament, corner, decisive turn, decisive moment, critical juncture, critical situation, trauma, quandary, extremity, disaster, trial, crux, climacteric, moment of truth, hour of decision, crossroads, climax, clutch*, pickle*, stew*, fix*, mess*, big trouble*, kettle of fish*, hot water, crunch*.
Antonyms normality, stability*, regularity*. See syn. study at emergency.emergency.