presumptive

Based on presumption or conjecture; inferred, likely, presumed.

Often postpositive, as in heir presumptive: of an heir or heiress: presumed to be entitled to inherit unless someone with a superior entitlement is born.

Of a cell or tissue: which has yet to differentiate, but is presumed to develop into a particular body part.

Synonym of presumptuous (“making unwarranted presumptions or assumptions, often out of arrogance or excessive self-confidence, and thus exceeding what is appropriate or right”).

Chiefly in presumptive evidence: providing a reasonable basis for a certain presumption or conclusion to be drawn.