Correct spelling for the English word "iridentropium" is [ˌɪɹɪdɪntɹˈə͡ʊpi͡əm], [ˌɪɹɪdɪntɹˈəʊpiəm], [ˌɪ_ɹ_ɪ_d_ɪ_n_t_ɹ_ˈəʊ_p_iə_m] (IPA phonetic alphabet).
Inversion of part of the iris.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.