Currency unknown following gold standard (8)
I believe the answer is:
ordinary
'standard' is the definition.
(I've seen this before)
'currency unknown following gold' is the wordplay.
'currency' becomes 'dinar' (I've seen this before**).
'unknown' becomes 'y' (algebra).
'following' says to put letters next to each other.
'gold' becomes 'or' ('or' is the heraldic name for gold).
'dinar'+'y'='dinary'
'dinary' put after 'or' is 'ORDINARY'.
(Other definitions for ordinary that I've seen before include "Commonplace, average" , "Unexceptional, quite usual" , "Unremarkable" , "Commonplace, avergae" , "'Commonplace, banal (8)'" .)