Resembling Capone and Eisenhower (5)
I believe the answer is:
alike
'resembling' is the definition.
(thesaurus)
'capone and eisenhower' is the wordplay.
'capone' becomes 'Al' (gangster Al Capone).
'and' says to put letters next to each other.
'eisenhower' becomes 'Ike' (Ike was a nickname of President Dwight Eisenhower).
'al'+'ike'='ALIKE'
(Other definitions for alike that I've seen before include "Resembling each other" , "Dull pain" , "In a similar way" , "twins, perhaps" , "uniform" .)