Very boring during a ball earlier (2,7)
I believe the answer is:
in advance
'earlier' is the definition.
Both the answer and definition are adverbs. Maybe there's an association between them I don't understand?
'very boring during a ball' is the wordplay.
'very' becomes 'v' (abbreviation).
'boring' means one lot of letters goes inside another (some letters must 'bore' a hole into other letters).
'during' becomes 'in' (I've seen this in other clues).
'ball' becomes 'dance' (I've seen this before).
'in'+'a'+'dance'='inadance'
'v' inserted inside 'inadance' is 'IN ADVANCE'.
Can you help me to learn more?
(Other definitions for in advance that I've seen before include "early" , "Ahead in place or time" , "Beforehand - can invade accordingly (2.7)" , "Before the event" .)