Score also picked up for mark in rugby (6-3)
I believe the answer is:
twenty-two
'mark in rugby' is the definition.
(line on rugby pitch 22 metres from goal-line)
'score also picked up for' is the wordplay.
'score' becomes 'twenty' (synonyms).
'also' means one lot of letters go next to another.
'picked up' shows a homophone (sound like).
'for' becomes 'to' (eg both can mean 'in the opinion of').
'to' sounds like 'two'.
'twenty'+'two'='TWENTY-TWO'
(Other definitions for twenty-two that I've seen before include "Two football teams" , "Line on rugby pitch; number" , "One more than this clue number" , "Number of players on pitch at start of soccer match" , "See 20" .)