Sports field (5)
'sports field' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for pitch that I've seen before include "Street seller's location" , "Set up a tent" , "perfect for some players" , "Throw or fall headlong" , "Field of play" .)
(Other definitions for arena that I've seen before include "The place of action" , "Ring; stadium" , "Area in centre of sports stadium" , "Place for public events" , "Area of combat" .)