The most common and most likely answer to this crossword clue is the 8 letter word ANOREXIC
A
N
O
R
E
X
I
C
More clues leading to the result ANOREXIC
Buddy explains!

The straight part
We know that "Wasted" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case wasted = anorexic.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does ANOREXIC mean?
ANOREXIC noun- Somebody suffering from anorexia nervosa.
- A medicine which suppresses appetite.
- Pertaining to, or suffering from anorexia nervosa.
- (by extension) Thin, skinny.