1) To simultaneously combine(unite/merge) two concepts by shortening off the top of one and the end of the other
2) When you start with one word and accidentally finish with another, but still get a point across (often by accident).
i.e. Combine + Truncate = Contruncate
Doctor: "Explain to me your problem."
Patient: "My mind outruns the speed at which I can talk, I combine and warp words together when I start one and finish with another. My friends say its ADHD. It's like I blend words left & and right, I accidentally contruncate them, SHOOT I DID IT AGAIN."