Pancake left in rubbish container on island (5)
I believe the answer is:
blini
'pancake' is the definition.
(blini is a kind of pancake)
'left in rubbish container on island' is the wordplay.
'left' becomes 'l' (common abbreviation).
'in' is an insertion indicator.
'rubbish container' becomes 'bin' (rubbish bin).
'on' means one lot of letters go next to another (in a down clue, letters appear on others).
'island' becomes 'i' (geographical abbreviation).
'l' inserted into 'bin' is 'blin'.
'blin'+'i'='BLINI'
(Other definitions for blini that I've seen before include "Russian food" , "Straw hat" , "Eastern European twenty four Ac" , "Pancakes served with sour cream" , "Small buckwheat pancake" .)