Suspect quiet day was wasted (5)
I believe the answer is:
shady
'suspect' is the definition.
(I know that suspect can be written as shady)
'quiet day was wasted' is the wordplay.
I cannot quite understand how this works, but
'quiet' could be 'sh' ('sh' is used to tell someone to be quiet) and 'sh' is found in the answer.
an anagram of 'day' is 'ady' which is located in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for shady that I've seen before include "underhand" , "Dishonest" , "Disreputable - umbrageous" , "Questionably legal" , "Fishy; unlit" .)