### Clue: Starchy Gaff's in a leather top (4)
### Answer: AMYL 
 ### Explanation: Definition: Starchy
 MY(first person possessive pronoun;self-reference by Gaff, the setter) **contained in**(in) [A + **first letter of**(top, in a down clue) "leather " ].
Answer: In biochemistry, pertaining to or of starch;starch-y, as in the names of compound substances related to starch.