Almost growing cereal fruit (6)
I believe the answer is:
raisin
'cereal fruit' is the definition.
(I've seen this in another clue)
'almost growing' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'growing' becomes 'raising' ('raise' can be a synonym of 'grow').
'raising' with its final letter taken off is 'RAISIN'.
(Other definitions for raisin that I've seen before include "Dried 18" , "A dried grape, nice in cake" , "Partially dried grape" , "An iris (anag)" , "Dried grape used in cakes" .)