The Collaborative International Dictionary
Hypotarsi
Hypotarsus \Hy`po*tar"sus\, n.; pl. Hypotarsi. [NL. See Hypo-, and Tarsus.] (Anat.) A process on the posterior side of the tarsometatarsus of many birds; the calcaneal process. -- Hy`po*tar"sal, a.
Wiktionary
hypotarsi
n. (plural of hypotarsus English)