In general, I bicker about an excuse (5)
I believe the answer is:
'an excuse' is the definition.
(excuse given by a suspect in an investigation)
'in general i bicker' is the wordplay.
'in' indicates the answer is hidden within the clue.
'ALIBI' is hidden in the letters of 'general i bicker'.
'about' is the link.
(Other definitions for alibi that I've seen before include "in order to prove I was elsewhere" , "Justification" , "Excuse for not doing something" , "Legal term from the Latin 'elsewhere'" , "Evidence one was not at crime scene" .)