Nimembeh was a male human Starfleet admiral in the 24th century. In 2368 Chakotay presented his resignation to the admiral personally.

Discrepancy note: In the novel Pathways Nimembeh is also an Academy instructor to both Chakotay and Harry Kim (Lt. Nimembeh for the former, Commander Nimembeh for the latter). However, Harry's experience with him would have also been in 2368, and "admiral" would have been too high a rank for the role Harry's Nimembeh took. Since the Admiral Nimembeh is canon, we are left positing a second Nimembeh at the Academy. It also becomes possible that Chakotay's Academy instructor became the Admiral Nimembeh instead of the Commander Nimembeh (as posited in Pathways).