Gold supported by Kuwaiti currency and yen standard (8)
I believe the answer is:
ordinary
'standard' is the definition.
(I've seen this before)
'gold supported by kuwaiti currency and yen' is the wordplay.
'gold' becomes 'or' ('or' is the heraldic name for gold).
'supported by' says to put letters next to each other (in a down clue, some letters hold up others).
'kuwaiti currency' becomes 'dinar' (I've seen this in another clue).
'and' says to put letters next to each other.
'yen' becomes 'y' (resembles the symbol for the currency of Japan).
'or'+'dinar'+'y'='ORDINARY'
(Other definitions for ordinary that I've seen before include "Commonplace, average" , "Normal, usual" , "Run-of-the-mill" , "Common-or-garden" , "Unremarkable" .)