### Clue: Lie about a small volume by current mathematician (9)
### Answer: FIBONACCI 
 ### Explanation: Definition: mathematician
 FIB(a lie;an untruth) ON(about;referring to) + [ A CC ](abbrev. for a cubic centimetre;a small volume) + I(the symbol for an electric current in physics).
Answer: Leonardo, the Italian mathematician in the Middle Ages.