abnego

Abnego, abnegare, abnegavi, abnegatum is first conjugation: ab plus nego, where the prefix intensifies rather than changes the sense. Two constructions. With a plain accusative it is "deny, disown" a person or a claim. With an accusative of the thing and a dative of the person it is "refuse X to Y" - auxilium alicui abnegare.

This corpus is heavily ecclesiastical, and that shows: by far the commonest uses are Peter's denial in the Gospels and the call to abnegare semet ipsum, "to renounce oneself". Classical prose barely bothers with the compound, because nego already covers the ground. Treat abnego as the raised voice rather than a separate verb, and note that the participle abnegatus is passive in the ordinary way, unlike the deponents nearby.