An abbreviation for the phrase 'literal spastic'. Usage cav vary depending on whether the subject is a temporary spastic, or, more common, if s/he is one by birth. It is polite to identify those who are normal, and those who are spastic. A litty spaz may be incapable of walking to the shop, they cannot articulate, and, more often than not, have no idea what they are doing at any particular moment. In general, their future is bleak.
'Look, mate, it's a litty spaz!'