[UN-1 6.] trans. To divest of substance; to render unsubstantial.

1

1799.  Coleridge, Lett. (1895), 284. Death!—that … so unsubstantiates the living things that one has grasped.

2

1819.  Chalmers, Congregat. Serm. (1836), I. 345. You unsubstantiate all the solemnity of his proclaimed sayings.

3

1881.  Fraser, Berkeley, 91. The premises that unsubstantiate matter, they would argue, unsubstantiate everything.

4