Care home doctor goes around (4)
I believe the answer is:
mind
'care' is the definition.
(I know that care is a more specific form of the action mind)
'home doctor goes around' is the wordplay.
'home' becomes 'in' (to be in is to be (at) home).
'doctor' becomes 'md' (synonyms).
'goes around' means one lot of letters goes inside another.
'in' placed inside 'md' is 'MIND'.
(Other definitions for mind that I've seen before include "'Out of sight, out of ....'" , "Look after" , "Brain" , "Object to; take care of" , "Seat of the faculty of reason" .)