Ruined rugby side's first point (8)
I believe the answer is:
bankrupt
'ruined' is the definition.
(thesaurus)
'rugby side's first point' is the wordplay.
'rugby' becomes 'ru'.
'side' becomes 'bank' (bank is a kind of side**).
'first' is a charade indicator (letters next to each other).
'point' becomes 'pt'.
'ru' after 'bank' is 'bankru'.
'bankru'+'pt'='BANKRUPT'
(Other definitions for bankrupt that I've seen before include "Skint" , "Broke" , "Person legally declared to be unable to pay debts" , "in Carey Street" , "on one's uppers" .)