Sleepy even around mid-afternoon (5)
I believe the answer is:
tired
'sleepy' is the definition.
(thesaurus)
'even around mid-afternoon' is the wordplay.
'even' becomes 'tied' ('tied' can be a synonym of 'even').
'around' means one lot of letters goes inside another.
'mid afternoon' becomes 'r' (I can't explain this - if you can you should believe this answer much more).
'tied' going around 'r' is 'TIRED'.
Can you help me to learn more?
(Other definitions for tired that I've seen before include "Worn-out" , "In need of rest" , "Are American cars so" , "In need of sleep" , "knackered" .)