A term used mostly among "{tweakers}" aka crystal meth users It refers to someone who is a little too high and not hiding it too well. They feel confident and in control but appear sloppy, messy and/or generally all over the place
I came home to find my roommate in the middle of at least 6 different elaborate projects involving power tools, cleaning supplies and and every major appliance either in use or being reconstructed.
Upon seeing the look on my face he asked what was wrong and I said:
"Your tweak is leaking."