Complained a busy worker had taken meals (6)
I believe the answer is:
beefed
'complained' is the definition.
(beefing is a kind of complaining)
'a busy worker had taken meals' is the wordplay.
'a busy worker' becomes 'bee' (I've seen this in another clue).
'had' means one lot of letters go next to another.
'taken meals' becomes 'fed' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'bee'+'fed'='BEEFED'
Can you help me to learn more?
(Other definitions for beefed that I've seen before include "Grumbled in meaty way" , "complained" .)