Work hard at and take a rest-break round about teatime (6)
I believe the answer is:
strive
'work' is the definition.
(thesaurus)
'rest-break round about teatime' is the wordplay.
'rest break' becomes 'st' (I am not sure about this - if you are sure you should believe this answer much more).
'round' means one lot of letters goes inside another.
'about' becomes 're' ('re' means regarding or about).
'teatime' becomes 'iv' (I've seen this in other clues).
're' placed around 'iv' is 'rive'.
'st'+'rive'='STRIVE'
'hard at and take a' is the link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for strive that I've seen before include "Try hard, carry on conflict" , "Try extremely hard" , "Building propped against the wall of another" , "Labour, try hard" , "Vie; compete" .)