御三時[osanji] three-o'clock snack
三鞭酒[shanpen] champagne
球面三角法[kyuumensankakuhou] spherical trigonometry
胸三寸[munesanzun] heart
元三[ganzan] New Year's period (January 1st to 3rd)

五十三次[gojuusantsugi] the 53 Toukaidou stages
向こう三軒[mukousangen] one's next three neighbors
降三世明王[gouzanzemyouou] Trailokyavijaya Vidya-raja
再三[saisan] again and again
再三再四[saisansaishi] repeatedly

一か八か[ichikabachika] sink or swim
嘘っ八[usoppachi] downright lie
嘘っ八百[usoppappyaku] full of lies
嘘八百[usohappyaku] full of lies
八釜しい[kamabisushii] noisy

口八丁[kuchihacchou] voluble
三十八度線[sanjuuhachidosen] the Thirty-eighth Parallel
四苦八苦[shikuhakku] being in dire distress
四通八達[shitsuuhattatsu] traffic network extending in all directions
四方八方[shihouhappou] in all directions

何時もより[itsumoyori] more than usual
御三時[osanji] three-o'clock snack
ある時[arutoki] once (i.e. "once, when I was studying ..")
安静時[anseiji] resting
安土桃山時代[azuchimomoyamajidai] Azuchi-Momoyama period (approx. 1558-1600 CE)

暗黒時代[ankokujidai] Dark Ages
育児時間[ikujijikan] nursing time
ひと時[ittoki] moment
一時に[ichidokini] at the same time
一時間[ichijikan] one hour