Definition of "neolithic"

With this thought in his mind, Challenger gave a contemptuous and condescending consent to the proposal that he should grace with his presence a proceeding which was, in his opinion, more fitted to the stone cabin of a neolithic savage than to the serious attention of one who represented the accumulated culture and wisdom of the human race.

1925 July – 1926 May, A[rthur] Conan Doyle, “(please specify the chapter number)”, in The Land of Mist (eBook no. 0601351h.html), Australia: Project Gutenberg Australia, published April 2019