Lewis and Short is a standard Latin lexicon from the end of the 19th century. I have the print form at home but it is massive. Now I can bring it with me wherever I go! Keep in mind that this is a scholarly dictionary, not a glossary. The entries are thorough, and give example quotations and citations. I am surprised some people say it did not have the words they needed. It has, I think, every word in classical Latin, and many from ecclesiastcal and medieval Latin, too. The complainers probably looked up the word in its inflected form, and were socked not to be able to find, say, "erroribus." Only flaw is that the Greek text in etymologies does not display properly.
Gheuf about Latin Dictionary