Assassination Depiction of the assassination of Abraham Lincoln shown in the presidential booth of Ford's Theatre, from left to right, are assassin John Wilkes Booth, Abraham Lincoln, Mary Todd Lincoln, Clara Harris and Henry Rathbone.
1. a murderer, esp. one who kills a politically prominent person for fanatical or monetary reasons. 2. (cap.) one of an order of Muslim fanatics, active in Persia and Syria c1090–1272, whose chief object was to assassinate Crusaders.