I am the friend in question. I can tell you this much: 1) I definitely don't use that word often. To my recollection, I've never typed it into my phone at all

I am the friend in question. I can tell you this much: 1) I definitely don't use that word often. To my recollection, I've never typed it into my phone at all, ever. 2) I had this reoccur with the phone that replaced it. 3) I explicitly deleted it from the keyboard dictionary both times, so this is not a case of my usage data following me to my new phone.