Obliterate: nearly washed out; indistinct.
Oblong: longer than broad.
Obovate: inversely egg-shaped; the narrow end downward.
Obpyriform: inversely pearshaped.
Obscure: not readily seen: not well defined.
Obsite-us: a surface covered with equal scales or other bodies.
Obsolete: nearly or entirely lost: inconspicuous.
Obtect: wrapped in a hard covering.
Obtected: applied to pupae when they are covered with a chitinous case which confines and conceals all appendages, though their outlines may be marked on the surface: see free, and coarctate.
Obtuse: not pointed: an angle greater than a right angle: opposed to acute. Obtuse-angulate: two markings or margins meeting so as to form an obtuse angle.