The name for a small unintentional shock of sticking up hair which cannot be flattened. This is usually found in the shorter hairs around the crown area of the (usually male) head. It occurs when the bearer needs to wash his hair or has washed and slept on it whilst wet (it can also occur on the side of the head). It is named after a British 1950s comic book character who fashioned the style.
Rod stewart hairstyles often contain jimpies.
Billy went to bed with his hair wet. He woke the next morning with a Jimpie on the side of his head. It would not flatten with water nor spit.