Some gent when sloshed gets shiner (8)
I believe the answer is:
gemstone
'shiner' is the definition.
(something which might shine)
'some gent when sloshed' is the wordplay.
'when sloshed' indicates an anagram.
'some'+'gent'='somegent'
'somegent' is an anagram of 'GEMSTONE'.
'gets' is the link.
(Other definitions for gemstone that I've seen before include "Something precious" , "Eg, sapphire" , "Eg, diamond or ruby" , "Jewel" , "Physical power" .)