Spoiled walk circling ends of tee (7)
'spoiled' is the definition.
(as in spoiling a child with treats)
'walk circling ends of tee' is the wordplay.
'walk' becomes 'tread' (treading is a kind of walking).
'circling' means one lot of letters goes inside another (circling can mean going around or containing).
'ends of' suggests removing the centre.
'tee' with its middle taken out is 'te'.
'tread' enclosing 'te' is 'TREATED'.
(Other definitions for treated that I've seen before include "Given medical care", "Given medical attention", "Doctored", "Applied medication to", "Nursed".)