I discovered a Latin spellchecking tool written by Karl Zeiler, which I have found very helpful. The dictionary itself is in the folder la. It is a Hunspell dictionary, which means it should work on multiple platforms. To get it to work on MacOS, you need to rename the files index.dic and index.aff to la.dic and la.aff and put them in ~/Library/Spelling/ Alternatively you could just download the latest version of LatinEdit and it will install them for you. There are instructions for other operating systems, but I haven't looked into how to do it.