My printed Oxford English Dictionary and online. The coining of the word actually pre-dates Charles Darwin's theory, and referred specifically to Erasmus' concept. IMHO, the OED is "the" standard source for correct English usage.
I wasn't trying to play *gotcha*, but to point out that there may be other less authoritative, or less august sources which still support the "Darwinism means evolution" populist usage.
(How many of the people on Jay Leno's Jaywalking -- not a decidedly fundamentalist group -- would define Darwinism as evolution, if they've heard of anything more than last week's American Idol?)
Cheers!