noun
signing ceremony
A formal event where a treaty, contract, or agreement is signed, often with officials present.
両国は平和条約の調印式を行った。
The two countries held a signing ceremony for the peace treaty.
署名式 is a more general term for a signing ceremony, while 調印式 specifically implies a formal agreement between parties, often in diplomatic or business contexts.
Compound of 調印 (signing, affixing a seal) and 式 (ceremony). The exact historical derivation is uncertain, but the word is conventionally associated with formal treaty signings.