"that obscures or darkens; that labors to prevent enlightenment," 1804, from French obscurant, from Latin obscurantem (nominative obscurans), present participle of obscurare "to make dark, darken, obscure," from obscurus (see obscure (adj.)).
oboe
obol
obreption
obscene
obscenity
obscurant
obscurantism
obscurantist
obscuration
obscure
obscurity