Postponement of transaction to acquire unfinished boat (8)
I believe the answer is:
deferral
'postponement' is the definition.
(I know that postponement can be written as deferral)
'transaction to acquire unfinished boat' is the wordplay.
'transaction' becomes 'deal' (a deal is a transaction or exchange).
'to acquire' indicates putting letters inside.
'unfinished' means to remove the last letter.
'boat' becomes 'ferry' (ferry is a kind of boat).
'ferry' with its last letter removed is 'ferr'.
'deal' placed around 'ferr' is 'DEFERRAL'.
'of' acts as a link.
(Other definitions for deferral that I've seen before include "shelving" , "Postponement" , "Adjournment" .)