14 letters · 19 points in Scrabble
adverb at the same instant
originEtymology tree English simultaneous Proto-Indo-European *leyg-der. Proto-Germanic *līkąder. Proto-Germanic *-līkaz Proto-Germanic *-ê Proto-Germanic *-līkê Proto-West Germanic *-līkē Old English -līċe Middle English -ly English -ly English simultaneously From simultaneous + -ly.
Etymology from Wiktionary, CC BY-SA 3.0