Nympha inclusa: = coarctate pupa; q.v.
Nymphipara: applied to insects that bear living young in an advanced stage of development: see also pupipara.
Ob-: as a prefix, means inversely.
Obconic: conic, with the apex pointing downward.
Obcordate: inversely heart-shaped, with the point applied to the base of another object or part.
Obese -us: unnaturally distended: usually applied to the abdomen.
Oblate: flattened; applied to a spheroid of which the diameter is shortened at two opposite ends.
Oblique: any direction between perpendicular and horizontal.
Oblique vein: in Odonata; an apparent cross-vein situated between M2 and Rs, distal to the level of the nodus and inclined obliquely, from its front end, backward and outward; in reality the basal part of Rs.