noun, noun or participle which takes 'suru', transitive verb
secret agreement; secret pact
Refers to a formal or informal agreement made in secret, often with political, business, or conspiratorial overtones. Can be used as a noun or with する to mean 'to make a secret agreement'.
両国は密約を結んだと報じられた。
It was reported that the two countries concluded a secret agreement.
彼らは裏で密約し
They seem to have made a secret pact behind the scenes.