Cross with one representative of this cricket side (6)
I believe the answer is:
eleven
This clue is a double definition.
'cross with one representative of this' is the first definition.
(Roman numerals XI)
'cricket side' is the second definition.
(a cricket team has 11 players)
(Other definitions for eleven that I've seen before include "Number on a side (6)" , "Odd number for a team" , "Number killed in the Peterloo massacre" , "Age to start secondary education" , "Not first team (6,6) - See 24" .)