Clement , prime minister from 1945-51 (6)
I believe the answer is:
attlee
(Other definitions for attlee that I've seen before include "Granny Smiths perhaps" , "5,27 [PRIME MINISTER]" , "Clement -, PM nineteen forty five - fifty one" , "Labour prime minister, d. 1967" , "Prime minister nineteen forty five to fifty one" .)