Pounce, seeing son parking outside court (5)
I believe the answer is:
swoop
'pounce' is the definition.
(I know that pounce can be written as swoop)
'son parking outside court' is the wordplay.
'son' becomes 's' (genealogical abbreviation for son).
'parking' becomes 'p' (abbreviation on road signs).
'outside' means one lot of letters goes inside another (some letters go outside others).
'court' becomes 'woo' (both can mean to romance someone).
's'+'p'='sp'
'sp' enclosing 'woo' is 'SWOOP'.
'seeing' acts as a link.
(Other definitions for swoop that I've seen before include "Police raid" , "Move rapidly down" , "Dive downwards" , "Pounce suddenly" , "Rush suddenly" .)