1. (try to) do more than you are capable or authorized to do
overreach your authority/self
To overreach can mean to reach out to far or to attempt to do more than is reasonably possible. To overreach can also mean to get the better of someone by outwitting or outsmarting them. As a noun and overreach refers to the movement of an animal with four legs whereby the hindlegs come forward and hit the forefeet causing an injury.