Where footballers play and train (6)
I believe the answer is:
ground
I believe this is a double definition.
'where footballers play' is the first definition.
(football ground)
'train' is the second definition.
(thesaurus)
'and' acts as a link.
(Other definitions for ground that I've seen before include "crushed into small particles" , "on which Pachelbel wrote his Canon?" , "Minced" , "foundation course?" , "Stadium; crushed" .)