Correct spelling for the English word "hectargyre" is [hˈɛktɑːd͡ʒˌa͡ɪ͡ə], [hˈɛktɑːdʒˌaɪə], [h_ˈɛ_k_t_ɑː_dʒ_ˌaɪə] (IPA phonetic alphabet).
One of a group of phenyl-sulphonic derivatives of mercury, employed in the treatment of syphilis, in conjunction with hectine, in hypodermic dose of gr. 1 1/2-3 (0.1-0.2) every other day, alternating with hectine.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.