Decreasing metal in goldfield, initially (7)
I believe the answer is:
ironing
'decreasing' is the definition.
(de-creasing: removing creases)
'metal in goldfield initially' is the wordplay.
'metal' becomes 'iron' (iron is a metal).
'initially' suggests taking the first letters.
The initial letter of 'goldfield' is 'g'.
'iron'+'in'+'g'='IRONING'
(Other definitions for ironing that I've seen before include "Household chore" , "Household task" , "Smoothing with heat" , "Items to decrease" , "A housework chore" .)