Look up, eating half of cold dry cheese (7)
I believe the answer is:
ricotta
'cheese' is the definition.
(ricotta is a type of cheese)
'look up eating half of cold dry' is the wordplay.
'look' becomes 'air' (something might have a certain air or look).
'up' says the letters should be written backwards (in down clue: letters go upwards).
'eating' is an insertion indicator.
'half of' indicates taking half.
'dry' becomes 'tt' (abbreviation for teetotal).
'air' in reverse letter order is 'ria'.
'cold' halved is 'co'.
'co'+'tt'='cott'
'ria' enclosing 'cott' is 'RICOTTA'.
(Other definitions for ricotta that I've seen before include "dairy produce" , "One soft cheese" , "Italian curd cheese" , "cheese found" , "one brought on board?" .)