Correct spelling for the English word "bidermoma" is [ba͡ɪdəmˈə͡ʊmə], [baɪdəmˈəʊmə], [b_aɪ_d_ə_m_ˈəʊ_m_ə] (IPA phonetic alphabet).
Didermoma, a teratoid growth representing two germ-layers.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.