A relative of the words jank and janky, but with extra letters. Created through an act of inscest between the words jank and janky, it is the bastard child that none of the jank family will claim.
The inside roof of Alex's G-Ride Bonnevile, which is presently bare metal, produces a jankety noise every time a door is slammed.
Adj., superlative: To be poorly designed, built, and/or maintained to such an extent that the user or observer is genuinely shocked that the system in question is stable or functional.
It may be the janketyassedest set we've ever built, so make sure your healthinsurance is in order.