Very much into morning working, then golf (5)
I believe the answer is:
among
'very much into' is the definition.
(among means in or amid something)
'morning working then golf' is the wordplay.
'morning' becomes 'am' (as in 12:00 AM).
'working' becomes 'on' (e.g. a machine is working or on).
'then' says to put letters next to each other.
'golf' becomes 'g' (phonetic alphabet: alpha, bravo, charlie etc.).
'am'+'on'+'g'='AMONG'
(Other definitions for among that I've seen before include "Amid" , "In the number of" , "when in company" , "In an assembly of" , "Go man! (anag.)" .)