The Collaborative International Dictionary of English v.0.48:
Substantiate \Sub*stan"ti*ate\, v. t. [imp. & p. p.
Substantiated; p. pr. & vb. n. Substantiating.]
1. To make to exist; to make real. --Ayliffe.
2. To establish the existence or truth of by proof or
competent evidence; to verify; as, to substantiate a
charge or allegation; to substantiate a declaration.
Observation is, in turn, wanted to direct and
substantiate the course of experiment. --Coleridge.
Moby Thesaurus II by Grady Ward, 1.0:
43 Moby Thesaurus words for "substantiated":
actual, ascertained, attested, authenticated, borne out,
categorically true, certain, certified, circumstantiated,
confirmed, corroborated, demonstrated, determined, documentary,
effectual, established, factual, fixed, historical, not in error,
objectively true, proved, proven, real, settled, shown,
sure-enough, true, true as gospel, truthful, unconfuted, undenied,
undoubted, unerroneous, unfallacious, unfalse, unmistaken,
unquestionable, unrefuted, validated, veracious, verified,