When two people spend too much time together and start to become the same person.
She's my twintilla, we open doors at the same time from opposite sides.
A word one adds to the end of another word to emphasize their point.
Omg, Thomas completely failed that math test, he's such a fail-tilla.
The point you get to when you are just so done that you can't even.
When I showed him my drawing of a snake, Logan was completely donetilla.