Meh is the verbal equivalent of shrugging your shoulders used to show that one simply do not care. It's also quite a versatile word. Could be used as a passive aggressive form of 'fuck.' It could be used synonymous with words like, alright, always, I dont really care, if you want, kind of, maybe, never, I dont care, no thankyou, ok, shut up, well, whatever, yes, yes please, etc.