Compounds of 三

• 宮中三殿
  (n) the palace sanctuary, shrine of imperial ancestors and temple inside the Japanese imperial palace
• 胸先三寸
  (n) one's mind
  one's inner feelings
  (a decision hinging on) how someone feels about it
• 五十三次
  (n) the 53 Toukaidou stages
  (P)
• 口三味線
  (n) humming a samisen tune
• 口三味線
  (n) humming a samisen tune
• 再三再四
  (adv,n) repeatedly
• 三々九度
  (n) three-times-three exchange of nuptial cups
• 三々五々
  (adv) in groups of twos and threes
  in small groups
• 三つ折り
  (n) threefold
  folded in three
• 三つ揃い
  (n) three-piece suit
• 三つ巴戦
  (n) playoff for the tournament win in sumo with three wrestlers participating
• 三つ編み
  (n) braid (hair, cord. etc.)
  plait
• 三位一体
  (n,adj-no) the Trinity
• 三井財閥
  (n) Mitsui Zaibatsu
• 三井住友
  (n) Mitsui Sumitomo
  Sumitomo Mitsui
• 三浦折り
  (n) Miura map fold
  special technique for folding used on some solar panel arrays
• 三猿主義
  (n) the principle (philosophy) of see no evil, hear no evil, speak no evil
  the policy of "see-not, hear-not, and speak-not"
• 三王礼拝
  (n) Adoration of the Magi
• 三下り半
  (n) letter of divorce
• 三化螟蛾
  (n) (uk) yellow stem borer (species of moth, Scirpophaga incertulas)
• 三界流転
  (n) endless cycle of rebirth through the three worlds of past, present, and future existences (Buddhist)
• 三角関係
  (n,adj-no) love triangle
  eternal triangle
• 三角関数
  (n) trigonometric function
• 三角測量
  (n) triangulation
• 三角定規
  (n) triangles (used in mechanical drawing)
  set square
• 三角闘争
  (n) three-cornered fight
• 三角函数
  (n) trigonometrical function
• 三角貿易
  (n) trilateral trade
• 三角木馬
  (n) ridged wooden bench used in SM practices (and in the Edo period for torturing female prisoners)
• 三割自治
  (n) the "thirty-percent autonomy" of local governments