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

ない交ぜにする[naimazenisuru] to blend (e.g. truth and lies)
データ交換[deetakoukan] data exchange
メール交換[meerukoukan] exchange of letters
リーダー交代[riidaakoutai] leadership change
意見交換[ikenkoukan] exchange of ideas

一方交通[ippoukoutsuu] one-way traffic
羽交絞め[hagaijime] pinioning
仮名交じり[kanamajiri] mixed writing (characters and kana)
仮名交じり文[kanamajiribun] mixed writing (characters and kana)
賀詞交換[gashikoukan] New Year greetings (parties)

お風呂に入る[ofuronihairu] to take a bath
鍬入れ式[kuwaireshiki] ground-breaking ceremony
塵入[gomiire] trashcan
キー入力[kiinyuuryoku] key (input)
ビジネススクール入学共通試験[bijinesusukuurunyuugakukyoutsuushiken] business school entrance test

メスを入れる[mesuwoireru] to operate
圧入[atsunyuu] indentation
移入[inyuu] importation
一寝入り[hitoneiri] nap
一入[hitoshio] still more