Monkey's puzzle \Mon"key's puz"zle\ (Bot.) A lofty coniferous Chilian tree ({Araucaria araucana}, formerly {Araucaria imbricata}), the branches of which are so crowded and intertwisted "as to puzzle a monkey to climb." It is also called {monkey puzzle} and {monkey puzzle tree}. The edible nuts are over an inch long, and are called pi[~n]on by the Chilians. [1913 Webster]