attested

adjective4

1. •
   Proven; shown to be true with evidence.
2. •
   Supported with testimony.
3. •
   Of words or languages, proven to have existed by records.

   • The word "slaepwerig" (sleep-weary) is attested in the Exeter Book in the form "slaepwerigne".
4. •
   Certified as good, correct, or pure.