The most common and most likely answer to this crossword clue is the 7 letter word TRIFLED
I've seen this crossword clue in The Guardian
T
R
I
F
L
E
D
More clues leading to the result TRIFLED
Buddy explains!

The straight part
We know that "Wasted time" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case wasted time = trifled.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 TRIFLED mean?
TRIFLED verb- To deal with something as if it were of little importance or worth.
- To act, speak, or otherwise behave with jest.
- To inconsequentially toy with something.
- To squander or waste.
- To make a trifle of, to make trivial.