Urge to use an iron (5)
I believe the answer is:
press
This clue is a double definition.
'urge' is the first definition.
(I know that urge can be written as press)
'use an iron' is the second definition.
(I've seen this in another clue)
'to' acts as a link.
(Other definitions for press that I've seen before include "Jam" , "Iron - clasp - newspapers" , "flock" , "Railroad" , "Crush; iron" .)