Italy yet to be beaten after second half (6)
I believe the answer is:
moiety
'half' is the definition.
(I've seen this before)
'italy yet to be beaten after second' is the wordplay.
'italy' becomes 'i'.
'to be beaten' indicates an anagram.
'after' means one lot of letters go next to another.
'second' becomes 'mo' (both are short periods of time).
'yet' is an anagram of 'ety'.
'i'+'ety'='iety'
'iety' put after 'mo' is 'MOIETY'.
(Other definitions for moiety that I've seen before include "Oy! Time for a half" , "Fair portion" , "Either of two" , "A legal sort of half" , "One of two equal parts" .)