slumber, sleep

REST
WordClue
NAPshort period of sleep
DOZElight, short sleep or nap
LULLperiod of rest
MASScritical or rest
ENERGYmental or rest
INSOMNIAinability to sleep
REMAINDERresidue, rest
LOCKsluice
MILLIONAIRESlumdog ... (film)