Definition of "by no means"

by no means

prepositional phrase
1. (idiomatic) certainly not; definitely not; not by any means.
  Quotations
  He by no means gave up his shop. On the contrary, he kept well abreast of new discoveries. He followed the great movement of chocolates; he was the first to introduce "cocoa" and "revalenta" into the Seine-Inferieure.
  1856: Gustave Flaubert, Madame Bovary, Part III Chapter XI, translated by Eleanor Marx-Aveling
  Well, during our short staycation at Humberston Fitties, just south of Cleethorpes, we cycled through the very unspoilt Lincolnshire Wolds, which are by no means flat and boring as conventional wisdom about the county suggests.
  2021 July 28, Christian Wolmar, “Forgotten by the railways, but ripe for the exploring”, in RAIL, number 936, page 35