An annoying little breed of dog created by a English Parson (similar to a minister or priest) named Jack Russell in the mid-1800's. The dogs are hyper and do not settle down until 7 or 8 years old. They are fearless but reckless and usually die unnatural deaths (ie. runover by cars, shot, beaten by bigger dogs or bears) due to their inability to stop being annoying. Usually, dumbass owner's name their own dog "Jack" or "Russell" or if female, "Jackie". This is annoying too and should be greatly discouraged!
That bastard of a neighbor's Jack Russell won't stop chasing my cat!