8 letters · 19 points in Scrabble
originFrom the nursery rhyme Rock-a-bye Baby, previously recorded as "Hush-a-by(e) baby"; blend of rock + lullaby or rock + -abye (as in hush-a-bye, from -a- (connective interfix) + bye (“goodbye, bye-bye”)).
Etymology from Wiktionary, CC BY-SA 3.0