Correct spelling for the English word "siagonantritis" is [sˌa͡ɪəɡˌɒnantɹˈa͡ɪtɪs], [sˌaɪəɡˌɒnantɹˈaɪtɪs], [s_ˌaɪ_ə_ɡ_ˌɒ_n_a_n_t_ɹ_ˈaɪ_t_ɪ_s] (IPA phonetic alphabet).
Inflammation of the maxillary sinus.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.