Carol, for example, providing good support for boy (4)
I believe the answer is:
song
'carol for example' is the definition.
(carol is a kind of song)
'good support for boy' is the wordplay.
'good' becomes 'g' (abbreviation).
'support for' means one lot of letters go next to another.
'boy' becomes 'son' ('son' can be a synonym of 'boy'**).
'g' put after 'son' is 'SONG'.
'providing' is the link.
(Other definitions for song that I've seen before include "You work best when on this" , "Vocal composition" , "Musical rendition" , "Words set to music" , "Lied" .)