6 letters · 13 points in Scrabble
noun an unexpected and inexplicable change in something (in a situation or a person's behavior, etc.)
originFrom Italian vagare (“wander”) and/or its source Latin vagārī (“to wander”), from Latin vagus (“wandering”). Later apparently reinterpreted in English as vague + -ery but without changing the spelling. By surface analysis, Latin vag(us) + -ary.
Etymology from Wiktionary, CC BY-SA 3.0