New editor on holiday drinking rum went to sleep (6,3)
I believe the answer is:
nodded off
'went to sleep' is the definition.
('nod off' can be a synonym of 'go to sleep')
'new editor on holiday drinking rum' is the wordplay.
'new' becomes 'n'.
'editor' becomes 'ed'.
'on holiday' becomes 'off' (I've seen this before).
'drinking' means one lot of letters goes inside another.
'rum' becomes 'odd' (I've seen this before**).
'n'+'ed'+'off'='nedoff'
'nedoff' going around 'odd' is 'NODDED OFF'.
(Other definitions for nodded off that I've seen before include "dozed" , "Fell asleep" .)