Deal with Davey finally making pact (6)
I believe the answer is:
treaty
'pact' is the definition.
(I know that pact is a type of pact)
'deal with davey finally' is the wordplay.
'deal with' becomes 'treat' (synonyms).
'finally' indicates one should take the final letters.
The final letter of 'davey' is 'y'.
'treat'+'y'='TREATY'
'making' acts as a link.
(Other definitions for treaty that I've seen before include "Formal agreement between governments" , "Ratified agreement between states" , "Contract, agreement" , "A pact between countries" , "Formal pact" .)