Memento - our vines, possibly (8)
I believe the answer is:
souvenir
'memento' is the definition.
(I know that memento can be written as souvenir)
'our vines possibly' is the wordplay.
'possibly' is an anagram indicator.
'our'+'vines'='ourvines'
'ourvines' with letters rearranged gives 'SOUVENIR'.
(Other definitions for souvenir that I've seen before include "something worth keeping" , "Reminder of holiday" , "Keepsake, memento" , "Reminder of past events" , "remember seeing this?" .)