Promised to be put on the payroll (7)
I believe the answer is:
engaged
'promised' is the definition.
(synonyms)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for engaged that I've seen before include "Occupied with business - about to marry?" , "tied up" , "Sweethearts may get it" , "Busy - fiancee" , "Given a ring" .)