Nickname for Eisenhower (3)
I believe the answer is:
ike
'nickname for eisenhower' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for ike that I've seen before include "President Eisenhower's nickname" , "Thirty fourth US president's nickname" , "Former US President (informally)" , "President Eisenhower" , "Nickname for Dwight Eisenhower" .)