Beau has time with new duke (5)
I believe the answer is:
dandy
'beau' is the definition.
(synonyms)
'time with new duke' is the wordplay.
'time' becomes 'day' (day is a kind of time).
'with' indicates putting letters inside.
'new' becomes 'n' (abbreviation as in New Testament NT).
'duke' becomes 'd' (abbreviation).
'n'+'d'='nd'
'day' going around 'nd' is 'DANDY'.
'has' is the link.
(Other definitions for dandy that I've seen before include "First-rate - fop" , "See 6" , "comic, 1937-2012" , "Foppish fellow" , "Old comic" .)