12 letters · 21 points in Scrabble
originEtymology tree English tranquil Proto-Germanic *-inōną Proto-Indo-European *-dyé- Proto-Germanic *-atjaną Proto-Indo-European *-tus Proto-Germanic *-þuz Proto-Germanic *-assuz Proto-Germanic *-inassuz Proto-West Germanic *-nassī Old English -nes Middle English -nesse English -ness English tranquilness From tranquil + -ness.
Etymology from Wiktionary, CC BY-SA 3.0