A cereal, and fruit (5)
I believe the answer is:
acorn
'fruit' is the definition.
(I know that acorn is a type of fruit)
'a cereal' is the wordplay.
'cereal' becomes 'corn' (corn is a kind of cereal).
'a'+'corn'='ACORN'
'and' acts as a link.
(Other definitions for acorn that I've seen before include "cup's content" , "From which a "tall oak" may grow" , "Fruit-seed of the oak" , "from which something bigger may develop" , "Tree seed" .)