冠婚葬祭[kankonsousai] important ceremonial occasions in family relationships
既婚[kikon] marriage
既婚者[kikonsha] married person
既婚男性[kikondansei] married man
求婚[kyuukon] marriage proposal

求婚広告[kyuukonkoukoku] matrimonial advertisement
求婚者[kyuukonsha] suitor
近親婚[kinshinkon] consanguineous marriage
金婚式[kinkonshiki] golden wedding (anniversary)
銀婚式[ginkonshiki] silver wedding (anniversary)

安全保障条約[anzenhoshoujouyaku] US-Japan Security Treaty
違約[iyaku] breach of contract
違約金[iyakukin] penalty for contract breach
一粒子既約[ichiryuushikiyaku] one particle irreducible (physics)
化学兵器禁止条約[kagakuheikikinshijouyaku] chemical weapons ban treaty

仮条約[karijouyaku] provisional treaty
会う約束[auyakusoku] rendezvous
会員規約[kaiinkiyaku] membership agreement (e.g. for a credit card)
解約[kaiyaku] cancellation of contract
確約[kakuyaku] firm promise