Meaning

adjective having a reasonable basis for belief or acceptance

adjective affording reasonable grounds for belief or acceptance

originPIE word *upó From pre- + Latin sūmptus + -ive, from Late Middle English presumptif, presumptijf (“based on presumption”), from Anglo-Norman presumptif and Middle French presumptif, présomptif (“based on presumption; of an heir or heiress: presumed to be entitled to inherit unless someone with a superior entitlement is born; presumptuous”) (modern French présomptif), and directly from their…

Etymology from Wiktionary, CC BY-SA 3.0