to verify something by supplying evidence; to corroborate or authenticate (verb)
to give material form or substance to something; to embody (verb)
Examples of word substantiate
About the worst anyone can substantiate is that Obama derailed another Democrat or two for using fake signatures to get on the ballot.
I have waited for many hours now for anyone to substantiate a word of what Shuster said.
More-over, those who used his name to substantiate their own pet notions, those who would quote and misquote him endlessly, would find it convenient to forget that it was he who insisted that no canal should be considered until the comparative advantages and disadvantages of all possible routes were examined firsthand by experienced people and according to uniform standards.
CQ reported that not only were they true, but transcripts of Jane's recorded calls substantiate them.
When you concoct facts that aren't there and then insist on them to "substantiate" your ignorance, then don't be surprised if people think you're not rational.