Part of Switzerland invested in a currency initially of gold (5)
I believe the answer is:
auric
'of gold' is the definition.
(auric means relating to gold)
'part of switzerland invested in a currency initially' is the wordplay.
'part of switzerland' becomes 'Uri' (Uri is a canton of Switzerland).
'invested in' is an insertion indicator.
'initially' indicates taking the first letters.
The first letter of 'currency' is 'c'.
'a'+'c'='ac'
'uri' inserted into 'ac' is 'AURIC'.
(Other definitions for auric that I've seen before include "made of gold" , "- Goldfinger (Bond)" , "Hugh -, Labour party leader" , "French composer" , "Of or containing gold" .)