(Νίκαρχος), historical.

1. An Arcadian officer among the Greek forces who went to assist the younger Cyrus. When the Greek generals were treacherously assassinated by Tissaphernes, Nicarchus was severely wounded, but not killed, and came and informed the Greeks of what had taken place. He was subsequently induced to go over to the Persians, taking about twenty men with him (Xen. Anab. 2.5.33, 3.3.5).