Boy lifting hot food (4)
I believe the answer is:
nosh
'food' is the definition.
(nosh is a kind of food)
'boy lifting hot' is the wordplay.
'boy' becomes 'son' (synonyms).
'lifting' says the letters should be written in reverse.
'hot' becomes 'h' (abbreviation eg on taps).
'son' in reverse letter order is 'nos'.
'nos'+'h'='NOSH'
(Other definitions for nosh that I've seen before include "A slang meal" , "Slangy food or meal" , "Food (coll)" , "eating this?" , "Eats" .)