Post one at the stopping place (7)
I believe the answer is:
station
'place' is the definition.
(synonyms)
'post one at the stopping' is the wordplay.
'post one' becomes 'sati' (I can't explain this - if you can you should believe this answer much more).
'at' becomes 'on' (location).
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'stopping' means one lot of letters goes inside another (stopping can mean blocking a gap).
'sati'+'on'='sation'
'sation' placed around 't' is 'STATION'.
Can you help me to learn more?
(Other definitions for station that I've seen before include "eg Temple Meads" , "Fixed stopping place for transport" , "Base, post" , "Place of duty, work" , "Waterloo perhaps" .)