I paid sentries for working -- people getting regular payments (13)
I believe the answer is:
'people getting regular payments' is the definition.
'i paid sentries for working' is the wordplay.
'for working' indicates anagramming the letters.
'ipaidsentries' is an anagram of 'STIPENDIARIES'.
(Another definition for stipendiaries that I've seen is "People who are paid".)