Getting cross, perhaps, in my play area before time (9)
I believe the answer is:
incorrect
'getting cross perhaps' is the definition.
(an incorrect answer might be marked with a cross)
'in my play area before time' is the wordplay.
'my' becomes 'cor' (both are expressions of surprise).
'play area' becomes 'rec' (short for recreation ground).
'before' means one lot of letters go next to another.
'time' becomes 't' (abbreviation).
'in'+'cor'+'rec'+'t'='INCORRECT'
(Other definitions for incorrect that I've seen before include "Place of refuge" , "Not accurate" , "False, wrong" , "Erroneous" .)