To borrow something from someone when you clearly have no intention of returning it or you intend to wait and see if they ever ask for it back.
I perma-borrowed my neighbor's lawn mower 14 months ago and he still hasn't asked for it back.
by College Professor March 23, 2008
Verb: to borrow, in a permanent manner. To borrow with neither inclination nor intent to return.
Last summer, I permaborrowed my buddy's sweater.
by Scaryberry January 21, 2004