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)

天魚[amago] land-locked variety of red-spotted masu trout (Oncorhynchus masou ishikawae)
御天気[otenki] weather
コール天[kooruten] corded velveteen
破天連[pateren] Portuguese Jesuits (in Japan in the 16th century)
天鵝絨[tengajuu] velvet

悪天[akuten] bad weather
悪天候[akutenkou] bad weather
悪天使[akutenshi] evil angels
旭日昇天[kyokujitsushouten] full of vigor and vitality (like the rising sun) (vigour)
一天[itten] the whole sky