Unusual getting second chances (4)
I believe the answer is:
odds
'chances' is the definition.
(thesaurus)
'unusual getting second' is the wordplay.
'unusual' becomes 'odd' ('odd' can be similar in meaning to 'unusual'**).
'getting' is a charade indicator (letters next to each other).
'second' becomes 's' (common abbreviation).
'odd'+'s'='ODDS'
(Other definitions for odds that I've seen before include "Perhaps even money" , "Gambler's chances" , "Take chances" , "at which one may be disagreeing" , "Betting likelihood" .)