From Longman Dictionary of Contemporary Englishset the seal on somethingset the seal on somethingBritish EnglishCOMPLETE to make something definite or complete In 1972, Nixon himself went to China to set the seal on the new relationship. → seal
Examples from the Corpus
set the seal on something• It set the seal on his depression; he was almost ready to go home.• His three-day tour set the seal on reconciliation between the two communities.