Parked extra trailer in street (3)
I believe the answer is:
sat
'parked extra' is the definition.
The definition and answer can be both to do with contact as well as being past participle verbs.
Perhaps they are linked in a way I don't understand?
'trailer in street' is the wordplay.
'trailer' becomes 'a' (I can't explain this - if you can you should believe this answer much more).
'in' means one lot of letters goes inside another.
'street' becomes 'st' (abbreviation).
'a' put inside 'st' is 'SAT'.
Can you help me to learn more?
(Other definitions for sat that I've seen before include "Relaxed" , "Posed (for an artist)" , "Used a chair" , "Took a seat and posed for a portrait" , "Took a chair" .)