In the old Looney Tunes cartoons, Wile E. Coyote's pursuit of the Road Runner is dogged. He simply will not give up. The Road Runner is dogged by the Coyote, who will not stop chasing him.
You see the word, dog, in the word dogged. It's no trick. If you are dogged, you are as stubborn and tenacious as a dog after a bone. If someone says you are dogged by bad luck, picture bad luck following you around like a puppy looking for dinner. Be careful here because the meaning difference brings about a change in pronunciation. If you are the stubborn one, pronounce it DOG-id (two syllables), but if someone is after you, you say DOGD (one syllable).
