One with renegotiated bail makes excuse (5)
I believe the answer is:
alibi
'excuse' is the definition.
(excuse given by a suspect in an investigation)
'one with renegotiated bail' is the wordplay.
'one' becomes 'i' (Roman numeral).
'with' means one lot of letters go next to another.
'renegotiated' indicates an anagram.
'bail' is an anagram of 'alib'.
'i' after 'alib' is 'ALIBI'.
'makes' acts as a link.
(Other definitions for alibi that I've seen before include "Evidence of (or excuse for) being somewhere else at the time" , "Timely plea?" , "Claim put to court" , "Pretext; court excuse" , "Legal excuse" .)