1.To be high on stimulants like Meth or coke.\r\n2.To work obsessively or compulsively on something.\r\n3.To adjust something.\r\n4.To be way wrong about something\n> 1.He did 4 fat ass lines, hes tweakin hard\n> 2.I was tweakin on my room for like 4 hours\n> 3.I was just Tweakin the carb on my truck\n> 4.you think the Boston Celtics are the best team ever..man your tweakin.\n