sudden

an unexpected alteration in condition, situation, or course

an unexpected and rapid death

movimiento brusco

a quick, unexpected change in position

un cambio de posición rápido e inesperado

an unexpected, quick movement or change in position or direction

ataque repentino

an abrupt and violent act of aggression

un acto de agresión abrupto y violento

an unexpected and serious situation requiring immediate action

a short, abrupt pull or twist

transformación repentina

a rapid and complete change in form, appearance, or character

describe una transformación que ocurre rápida e inesperadamente

a fierce and destructive attack that begins unexpectedly

a formal term for an unexpected and rapid end, especially of a person or institution