Satisfy publican, at first, with tenancy agreement (6)
I believe the answer is:
please
'satisfy' is the definition.
(pleasing is a kind of satisfying)
'publican at first with tenancy agreement' is the wordplay.
'at first' indicates taking the first letters.
'with' is a charade indicator (letters next to each other).
'tenancy agreement' becomes 'lease' (I've seen this before).
The initial letter of 'publican' is 'p'.
'p'+'lease'='PLEASE'
(Other definitions for please that I've seen before include "It's said to help" , "Satisfy or gratify" , "Polite word of request" , "Delight, gladden" , "'Delight, gratify (6)'" .)