1. To become out of equilibrium; to become not straight, level, or aligned properly; to be in a state of chaos or confusion. Between my divorce, the death of my best friend, and the financial troubles at work, it seems like everything in my life has gotten off-kilter recently. John got a little off-kilter after being knocked in the head in football practice earlier.
2. To stop working correctly or properly; to be or become out of order; to be out of w(h)ack. It sounds like your car's engine has gotten a bit off-kilter. I'd recommend taking it to a mechanic before you go for any long drives.
See also: get