What is the meaning of Unsubstantiate?

To prove false; to disprove or discredit.

To officially categorize (an allegation) as unsubstantiated.

To call into question; to create doubt about.

To make insubstantial or abstract; unsubstantialize.

Lacking substance; insubstantial.

Unsubstantiated; unproven.

Source: wiktionary.org