Lingers over tucking into quantities of American wine (7)
I believe the answer is:
loiters
'lingers' is the definition.
('loiter' can be a synonym of 'linger')
'tucking into quantities of american wine' is the wordplay.
'tucking into' indicates putting letters inside.
'quantities' becomes 'ls' (l is a kind of quantity).
'of' becomes 'o''.
'american wine' becomes 'iter' (I am not sure about this - if you are sure you should believe this answer much more).
'o'+'iter'='oiter'
'ls' placed around 'oiter' is 'LOITERS'.
'over' is the link.
Can you help me to learn more?
(Other definitions for loiters that I've seen before include "Hangs about with toilers" , "Waits idly" , "Hangs about idly" , "dawdles" , "Hangs around" .)