I object. Ready outside without a treatment (6)
I believe the answer is:
remedy
'a treatment' is the definition.
(I know that remedy is a type of treatment)
'i object ready outside without' is the wordplay.
'i object' becomes 'me'.
'outside' says to hollow out the word (remove centre letters).
'without' means one lot of letters goes inside another.
'ready' with its centre removed is 'redy'.
'me' put within 'redy' is 'REMEDY'.
(Other definitions for remedy that I've seen before include "fix" , "Put right, be a cure for" , "Cure for illness" , "Curative medicine" , "Countermeasure" .)