By definition wetawded is an adjective used to describe someone or something that is not working correctly or at full potential. Usually this is brought on by lack of sleep, illness, or by use of alcohol or drugs. However, it can be used to describe the effects a mood has on a person as well. Most commonly it is used as a silly way to point out self-retardation on a subject, or a temporary state of not understanding something due to one of the above reasons.
Coming from the original word 'retard', or 'retarded', wetawd or wetawded may take it's place in any sentence. It is used to 'poke fun' at it's mother word 'retard'. By doing so it is not as offensive or harsh. It also implies a sense of irony, in that you are too retarded to actually pronounce the word correctly.
You may also use the word wetawd when watching someone do something really, really stupid.
1) I cannot function today I am totally wetawded. 2)What's wrong with you? Are you a wetawd? 3) Get a clue and stop being such a wetawd. 4) I am not wetawded... at least not yet. 5) What the **** is wrong with that guy? What a total wetawd!