Consult Bobcat or the Librarian for French Language and Literature for additional materials. You can combine search terms in BobCat. Imbs, Paul, ed. Editions du CNRS, 1971. A dictionary of the French language of the 19th and 20th centuries.
Extensive coverage includes etymology, history, pronunciation, statistical usage, and more.
Robert, Paul, ed. Le Robert, 1985. An excellent tool for researching pronunciation, etymology, history, and usage of French words. Collins Robert Comprehensive French English Dictionary . Harper Collins, 1995.