The term 'sudden' is used to describe something that happens quickly and unexpectedly. Crossword solutions for this term include 'UNFORESEEN' (10 letters), 'EXPEDITIOUS' (11 letters), 'RASH' (4 letters), 'UNANTICIPATED' (13 letters), 'RECKLESS' (8 letters), 'IMPETUOUS' (9 letters), 'UNPLANNED' (9 letters), 'FLEET' (5 letters), 'IMMEDIATE' (9 letters), 'PRECIPITANT' (11 letters), 'HURRIED' (7 letters), 'RUSHING' (7 letters), 'BRIEF' (5 letters), 'SNAP' (4 letters), 'IMPULSIVE' (9 letters), 'SPEEDY' (6 letters), 'HASTY' (5 letters), 'SURPRISING' (10 letters), 'IMPATIENT' (9 letters), 'HEADLONG' (8 letters), 'PRECIPITATE' (11 letters), 'QUICK' (5 letters), 'SHARP' (5 letters), 'ABRUPT' (6 letters), 'IMPACT' (6 letters), 'INSTANT' (7 letters). All of these words are used to describe something that happens suddenly, without warning or preparation.