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

お大事に[odaijini] take care of yourself
暗黒大陸[ankokutairiku] Dark Continent (i.e. Africa)
伊勢大神宮[isedaijinguu] the Grand Shrines of Ise
伊勢大廟[isetaibyou] the Grand Shrines of Ise
偉大[idai] greatness

医科大学[ikadaigaku] medical school
医大[idai] medical university
井の中の蛙大海を知らず[inonakanokawazutaikaiwoshirazu] parochial
一大[ichidai] one large ...
一大事[ichidaiji] serious affair

おけさ節[okesabushi] style of Japanese folk song associated with Niigata Prefecture
双節棍[nunchaku] nunchaku (two linked fighting sticks)
一音節[ichionsetsu] monosyllable
一節切り[hitoyogiri] one-jointed bamboo musical instrument
音節[onsetsu] syllable

鰹節[katsubushi] katsuobushi
環節[kansetsu] segment (of worm)
関節[kansetsu] joints (knee joint, elbow joint, etc.)
関節リューマチ[kansetsuryuumachi] rheumatoid arthritis
関節炎[kansetsuen] arthritis