sleep

REST
WordClue
NAPshort period of sleep
DOZElight, short sleep or nap
LULLperiod of rest
MASScritical or rest
ENERGYmental or rest
ASPHYXIAapnea
INSOMNIAinability to sleep
REMAINDERresidue, rest
MALLETsledgehammer
ROOMsleeping or control