Lord with yen to be in good time (5)
I believe the answer is:
early
'be in good time' is the definition.
(being early is arriving in good time)
'lord with yen' is the wordplay.
'lord' becomes 'earl' (earl is a kind of lord).
'with' means one lot of letters go next to another.
'yen' becomes 'y'.
'earl'+'y'='EARLY'
'to' is the link.
(Other definitions for early that I've seen before include "Opening" , "Immature" , "In good time" , "in the morning?" , "Before due time" .)