I hate the word shottie, too. It has the same number of letters and syllables as shotgun, so I'm not even sure how using shottie is lazy or convenient. It sounds more like an old POS car or a small, ankle-biting, English dog. Although I don't use it, I think hoody is a suitable abbreviation for "hooded sweat shirt." I didn't know what "addy" even was; I figured it was something Australian.