サンプリング周波数[sanpuringushuuhasuu] sampling frequency
一周忌[isshuuki] first anniversary of death
一周期[isshuuki] period (in astronomy)
一周年[isshuunen] one full year
円周[enshuu] circumference

円周率[enshuuritsu] Pi (3.1415926..)
外周[gaishuu] outer circumference
基本周波数[kihonshuuhasuu] fundamental frequency
月経周期[gekkeishuuki] menstrual cycle
周章てる[awateru] to become confused (disconcerted, disorganized, disorganised)

西貢[saigon] Saigon
瑞西[suisu] Switzerland
西藏[seizou] Tibet
新西蘭[nyuujiirando] New Zealand
伯剌西爾[burajiru] Brazil

墨西哥[mekishiko] Mexico
以西[isei] ... and westward
関西[kansai] Kansai (south-western half of Japan, including Osaka)
関西辯[kansaiben] Kansai dialect
古今東西[kokontouzai] all times and places