静謐[seihitsu] peacefulness

安静[ansei] rest
安静時[anseiji] resting
閑静[kansei] quiet (e.g. neighbourhood, neighborhood)
頸静脈[keijoumyaku] jugular vein
寝静まる[neshizumaru] to fall asleep

静か[shizuka] quiet
静けさ[shizukesa] stillness
静岡県[shizuokaken] Shizuoka prefecture (Chuubu area)
静穏[seion] serene
静観[seikan] watchful waiting