Mistake by the soccer authority last month (5)
I believe the answer is:
fault
'mistake' is the definition.
(synonyms)
'by the soccer authority last month' is the wordplay.
'by' means one lot of letters go next to another.
'the soccer authority' becomes 'fa' (I can't explain this - if you can you should believe this answer much more).
'last month' becomes 'ult' (short for 'last month' in correspondence).
'fa' next to 'ult' is 'FAULT'.
Can you help me to learn more?
(Other definitions for fault that I've seen before include "Defect or offence" , "Defect; blunder" , "Defect, mistake" , "Shortcoming" , "Defect; culpability" .)