Presumptive (adjective)

1. Based on assumption or probability without proof.
2. Assuming or indicating that something is likely to be true, without evidence to confirm it.

Origin:

Late 16th century from latin praesumptivus, from praesumere "take beforehand".

Examples:

1. The weatherman gave a presumptive forecast of rain tomorrow.
2. The detective had a presumptive understanding of the situation, but needed further evidence to confirm it.
3. The company gave him a presumptive offer, which he accepted with some reservations.
4. He had a presumptive right to the property, but needed to prove it in court.
5. The judge made a presumptive ruling, which was later overturned on appeal.