Grow weary about circular diatribe (6)
I believe the answer is:
tirade
'diatribe' is the definition.
(I've seen this in another clue)
'grow weary about circular' is the wordplay.
'grow weary' becomes 'tire' (synonyms).
'about' means one lot of letters goes inside another.
'circular' becomes 'ad' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'tire' going around 'ad' is 'TIRADE'.
Can you help me to learn more?
(Other definitions for tirade that I've seen before include "Verbal onslaught" , "Broadside of denunciation" , "Inclination; fish" , "Verbal outburst" , "Sustained abuse" .)