I had never seen or heard of the word "devotement" until reading it in my Chinese girlfriend's brother's college application essay. To me, it's always been "devotion." However, I noticed that Google Drive was not marking it as an unknown word, so I looked it up on Google. Turns out it's defined in plenty of online dictionaries with a definition equivalent to that of "devotion." It even exists in thesauruses. But for the life of me, I could not find something that talked about when you would use "devotement" instead of "devotion", or how such a similar word ended up in usage. Even now, Chrome's spell check doesn't like that I've placed "devotement" in this paragraph. Why Drive's spellcheck doesn't complain when Chrome's does... only adds to the mystery for me.
Can anyone clear this up for me? Why does "devotement" exist? When would one use it?