I’m not sure, but I imagine you are similar. As solid as your vocabulary is, sometimes you HAVE to utilize a NEW word. It just flows. The people you are with are on the thought train, the contextual environment understood, so it just happens. A word that does not exist, suddenly must. But what to do when auto-correct mangles said word into something arcane, or at worst offensive? Inside jokes are usually only funny if used in just the right way, and spelled correctly-ish. Congratulations, you have been inducted into the hallowed echelons of the wordsmith. Here is how to incorporate these new words into your device so they do not fade.
A. Go to Settings, General, Keyboard, International Keyboard, Add New Keyboard, select Japanese Ten Key.
Go back to the first Keyboard page, select ~Edit User Dictionary~. Tap the ~(+)~ in the top right-hand corner, then tap ~Word~.
You can now add any word you want your iPhone to recognize.