14 letters · 17 points in Scrabble
noun an effort above and beyond the call of duty
originFrom Late Latin superērogātiō (“payment in addition”), from superērogāre (“to pay in addition”), from super (“in addition to”) + ērogāre (“to pay, pay out, expend, disburse”), equivalent to supererogate + -ion.
Etymology from Wiktionary, CC BY-SA 3.0