Adviser provides the odd idea (4)
I believe the answer is:
aide
'adviser' is the definition.
'the odd idea' is the wordplay.
'the odd' indicates an anagram.
'idea' anagrammed gives 'AIDE'.
'provides' acts as a link.
(Other definitions for aide that I've seen before include "Leader's assistant" , "Political assistant" , "Officer who acts as military assistant" , "Adviser or assistant" , "Somebody helping" .)