That's funny. This is what your link actually says :-
Main Entry: ra·tio·nal·ism
Pronunciation: \ˈrash-nə-ˌli-zəm, ˈra-shə-nə-ˌli-\
Function: noun
Date: 1827
1 : reliance on reason as the basis for establishment of religious truth 2 a : a theory that reason is in itself a source of knowledge superior to and independent of sense perceptions b : a view that reason and experience rather than the nonrational are the fundamental criteria in the solution of problems
Main Entry: ra·tio·nal·ism
Pronunciation: \ˈrash-nə-ˌli-zəm, ˈra-shə-nə-ˌli-\
Function: noun
Date: 1827
1 : reliance on reason as the basis for establishment of religious truth 2 a : a theory that reason is in itself a source of knowledge superior to and independent of sense perceptions b : a view that reason and experience rather than the nonrational are the fundamental criteria in the solution of problems