The Collaborative International Dictionary
Simon-pure \Si"mon-pure"\, a. Genuine; true; real; authentic; -- a term alluding to the comedy character Simon Pure, who is impersonated by another and is obliged to prove himself to be the ``real Simon Pure.''
Douglas Harper's Etymology Dictionary
1815, from the true Simon Pure "the genuine person or thing" (1795), from Simon Pure, name of a Quaker who is impersonated by another character (Colonel Feignwell) in part of the comedy "A Bold Stroke for a Wife" (1717) by Susannah Centlivre, English dramatist and actress. The real Simon Pure is dealt with as an imposter in the play and is believed only after he has proved his identity.
Wiktionary
a. 1 absolutely pure. 2 genuine; real; authentic
Usage examples of "simon-pure".
Or, maybe you Talents are too simon-pure to lower yourselves to out right blackmail.
Jill, a man who is the Simon-pure legitimate child of three different parents.
But even if both of us were Simon-pure North European stock, certified by the American Kennel Club, (a silly notion, since the amount of casual bastardy among humans is far in excess of that ever admitted)-but even if we were, such ancestry would merely tell us which cannibals we are descended from.