Nanny runs off, with me being raised on benefit (9)
I believe the answer is:
nursemaid
'nanny' is the definition.
(both can mean someone who looks after children)
'runs off with me being raised on benefit' is the wordplay.
'off' indicates an anagram.
'with' means one lot of letters go next to another.
'being raised' says the letters should be written in reverse (going up in a down clue).
'on' means one lot of letters go next to another.
'benefit' becomes 'aid' (I've seen this in another clue).
'me' in reverse letter order is 'em'.
'runs' anagrammed gives 'nurs'.
'nurs'+'em'+'aid'='NURSEMAID'
(Other definitions for nursemaid that I've seen before include "Girl tending young children" , "caretaker" , "One looking after children" , "child minder" , "tender" .)