copay /ˈkoʊˌpeɪ/noun 1verb 1forms 3 noun1 •A copayment.The White House announced that, starting next year, Medicare copays for insulin will be capped at $35. Recipients who select drug plans with the new benefit could save about $450 a year. — 2020 verb1 •To jointly pay with another or others. formscopaid · copaying · copays