Used to describe an amazingly cool person in the south of England but refers to a moronic retard in the North, Wales and Scotland. Can be used to mean beer in Ireland and in most places of the UK
Person 1: How's your time in Manchester ?
Person 2: Fine apart from my new room mate is a complete jackalaka
Person 1: Thats a shame. Maybe you should throw him out the window whilst you sleep
Person 2: That's a bit mean. He isn't that bad a jackalaka unlike my classmate Jack.
A word that describes the physical aspect of the male climax ("jack") and the emotional ("elation") coined accidently by Dragon dictating software when I dictated the word "ejaculation" (as mentioned in the forthcoming book "Male Pelvic Fitness: Optimizing Sexual and Urinary Health").