怠い[darui] sluggish
過怠[katai] negligence
休怠[kyuutai] laziness
勤怠[kintai] diligence and indolence
倦怠[kentai] languor

けん怠感[kentaikan] physical weariness
倦怠期[kentaiki] the stage of fatigue
怠ける[namakeru] to be idle
怠け者[namakemono] lazy person
怠らずに[okotarazuni] carefully