SUDDEN Etymology: Middle English sodain, from Middle French, from Latin subitaneus, from subitus sudden, from past participle of subire to come up, from sub- up + ire to go -- more at SUB-, ISSUE1 a : happening or coming unexpectedly b : changing angle or character all at once 2 : marked by abruptness or haste 3 : made or brought about in a short time : PROMPT synonym see PRECIPITATE synonyms PRECIPITATE, HEADLONG, ABRUPT, IMPETUOUS, SUDDEN mean showing undue haste or unexpectedness.

~irks me when 'sudden' used simply as ~unexpected, esp when time is not an aspect -- when circumstance that are relatively static are decribed as 'all of sudden' bcs not what the speaker expected