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

今春[konshun] this spring
昨春[sakushun] last spring
三春[sanshun] three spring months
思春期[shishunki] puberty
春たけなわ[harutakenawa] spring is in full swing

春めく[harumeku] to become spring-like
春一番[haruichiban] first storm of spring
春夏秋冬[shunkashuutou] spring, summer, autumn (fall) and winter
春画[shunga] shunga