Playing field seconds from new free school redeveloped (3)
I believe the answer is:
rec
'playing field' is the definition.
(recreation ground)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for rec that I've seen before include "pleasure area" , "record" , "place for outdoor games" , "Sporting venue" , "Recreation ground (informal)" .)