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1.
A very hyper dog that can also be your best friend in the world!
Boy, that jack russell sure does love humpin thangs! I had to rip him off the neighbors cat eairlier!
by Jam_the_surfer June 25, 2007
 
2.
the most hyper annoying crazy dogs in the world. well sometimes lol they are very fast . sometimes they can be the funnyest dogs ever . but also ur best bud :)
simon, harley, jessey, pepper, jack russell
by mysterious lover;) March 15, 2010
 
3.
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!
by Defcon 4 and waiting June 20, 2010