From Longman Dictionary of Contemporary Englishposteritypos‧ter‧i‧ty /pɒˈsterəti $ pɑː-/ noun [uncountable] formalFUTUREall the people in the future who will be alive after you are deadpreserve/record/keep etc something for posterity
a priceless work of art that must be kept for posterityExamples from the Corpusposterity• It is hard to know now whether Eden was really being serious, or merely protecting himself for posterity.• Not only would that furtherdamage his image for posterity.• It so happens that Parrhasios composed his own review for posterity, namely the epitaphinscribed on his tombstone.• If you want your hand written words of wisdomsaved for posterity use quality paper and permanentink.• Perhaps she simply wanted to hear herself perform, unless of course she hoped to leave posterity an example of her playing.• Such a pleasure I hope is before us and our posterity under the influence of the new government...• One can imagine them forthrightly shaking hands and congratulating and thanking each other, but the words are lost to posterity.preserve/record/keep etc something for posterity• This wiseprecautionpreserved the Garden for posterity.• All V-Discs were to be destroyed after the war, but the Smithsonian kept a set for posterity, thankfully.