A stress developed about parking invasion (8)
I believe the answer is:
trespass
'invasion' is the definition.
(thesaurus)
'a stress developed about parking' is the wordplay.
'developed' is an anagram indicator.
'about' indicates putting letters inside.
'parking' becomes 'p' (abbreviation on road signs).
'a'+'stress'='astress'
'astress' with letters rearranged gives 'tresass'.
'tresass' going around 'p' is 'TRESPASS'.
(Other definitions for trespass that I've seen before include "Enter another's property without permission" , "Enter someone else's property illegally" , "Action of intruder" , "Illegally entering" , "Go out of bounds" .)