expression, noun-modifying (irregular)
fully-fledged; respectable; clear; accepted
Used prenominally to describe someone or something that is undeniably established, legitimate, or respectable. Often carries a nuance of being beyond doubt or clearly recognized.
彼はれっきとした医者だ。
He is a fully-fledged doctor.
これはれっきとした事実です。
This is an undeniable fact.