11 letters · 18 points in Scrabble
adverb without knowledge or intention
originFrom Middle English on-wytyngly, un-wetandly, unweteynglye, unwetinglie, un-wetinglye, unwetyngly, unwitandly, unwitendely, unwitingly, unwittandly, unwityngli, unwityngly, unwytyngeleche, unwytyngli, equivalent to unwitting + -ly or un- + wittingly.
Etymology from Wiktionary, CC BY-SA 3.0