Definition of well-proven in English:

well-proven

Pronunciation /wɛlˈpruːvən/ /wɛlˈprəʊvən/

adjective

Scottish
  • Fully demonstrated, tested, or tried; (hence) reliable, trustworthy.

Origin

Mid 17th century; earliest use found in Declinatour & Protestation Pretended Bishops. From well + proven.