"Lost an engine" is how we refer to an engine failure. When you use a term frequently enough you forget that the specific usage is not universally understood.

There have been a number of incidents and accidents where the engines have litterally been lost. The engine pylons are designed to have a weak link so that a seriously damaged engine will come loose instead of transmitting extreme forces to the airframe. Three incidents come immediately to mind though I'm sure that there have been more. AA191 departing ORD in the late 1970s is one example. At least one B727 had an engine depart the airframe during cruise on the southwest US. A cargo B747 had an engine break lose near Anchorage.

A failed engine is an emergency (in a two-engined airplane at least) but it is one of the most practiced emergency procedures and should not cause an accident unless there are aggravating factors. The airplanes are designed to do it.