Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Clītarchus, i, m., = Κλείταρχος, a companion of Alexander the Great, of whose life he wrote a history, Cic. Fam. 2, 10, 3; id. Leg. 1, 2, 7; id. Brut. 11, 42; Curt. 9, 5, 21 al.