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
To substantiate a statement or a story means to supply evidence which proves that it is true. There is little scientific evidence to substantiate the claims. = validate + substantiation sub·stan·tia·tion There may be alternative methods of substantiation other than written records. to prove the truth of something that someone has said, claimed etc