Pomegranate syrup's missing in pineapples (8)
I believe the answer is:
grenades
'pineapples' is the definition.
'pomegranate syrup's missing in' is the wordplay.
'pomegranate syrup's' becomes 'grenadines'.
'missing' indicates named letters should be taken away.
'grenadines' with 'in' removed is 'GRENADES'.
(Other definitions for grenades that I've seen before include "Hand-held explosives" , "Grandees holding small bombs" , "Small bombs thrown by hand" , "Small explosive hand-bomb" , "Small hand-bombs" .)