Correct spelling for the English word "Assident" is [ɐsˈa͡ɪdənt], [ɐsˈaɪdənt], [ɐ_s_ˈaɪ_d_ə_n_t] (IPA phonetic alphabet).
Concomitant.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
Associating with or sitting by others-applied to symptoms or signs of a disease.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.