What's missing from matzo (5)
I believe the answer is:
yeast
'what's missing from matzo' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for yeast that I've seen before include "Androgynous" , "Fungi used in bakery" , "Brewer" , "fermenter" , "Baker's raising agent" .)