Correct spelling for the English word "headgrit" is [hˈɛdɡɹɪt], [hˈɛdɡɹɪt], [h_ˈɛ_d_ɡ_ɹ_ɪ_t] (IPA phonetic alphabet).
An epizootic in sheep, sheep cholera; called also jaundice, yellows, and plocach.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.