Yes, "get wasted" is informal. There are hundreds of similar expressions... get maggoted, get sloshed, get pissed, get rotten, get flogged, get pickled, get trashed... I wouldn't think too much about the precise meaning of "wasted". I guess it refers to the messy state that people achieve when they are too drunk. As though you've reduced yourself to the value and usefulness of a piece of rubbish/waste. "Wasting your life/time/day" doesn't equate to "getting wasted".

"Wasted" generally means taking too much of any drug (mind altering substance). "Drunk" means drinking to much alcohol. It can also mean feeling as if you have had too much alcohol as in "love drunk". These websites should help you with these kinds of questions.: http://www.peevish.co.uk/slang/links.htm#us%20slang http://www.goodwords.com/amerispeak/ http://slangcity.com/ http://www.urbandictionary.com/ http://onlineslangdictionary.com/

Just to add to the above answers Get wasted is often used more to describe the effects of drug use rather than those of drinking, or at least it is here where I come from south England. Get wasted can also be used to describe effects of drink and or drugs where as get drunk, sloshed, pissed etc etc can only be used to describe the effects of drinking.

They have nearly the same meaning. However, 'get wasted' is an informal expression meaning 'to be strongly affected by alcohol' and it can be replaced by other expressions such as 'get drunk', 'be under the influence of alcohol', 'blind drunk'...

afaiu, get wasted means spending time without any benefit - it may be either drinking alcohol, or just simple hanging out with friends