Definitions

1. adjective

relating to or characterized by the theory of Jean-Baptiste Lamarck that organisms acquire characteristics through use and disuse, and that these characteristics can be passed on to their offspring.

“The Lamarckian theory of evolution was widely debated among scientists in the 19th century.”

2. noun

a person who holds or advocates the Lamarckian theory of evolution.

“The Lamarckian was a vocal critic of the new Darwinian theory of evolution.”