I ran into a weird issue last night. I was texting someone my real live last name and the predictive word app offered me several followup words that I found odd.
Such as eccie, and slingblade. I have logged on with a private browser on this phone. I though it would be safe. I guess its not. Also this morning its not doing it anymore.
It's your keyboard app that stores your auto correct or predictive word data, not your browser.
Go to settings......apps......all. Then find the keyboard app(s) you're using and select it. Then hit clear data. All of your auto correct and predictive text data will be gone.
Obviously, you'll want to do this every so often.
fwiw, if you are sharing that phone with anyone outside the hobby, prolly better to just shut off the predictive typing entirely.