Sebific duct: carries the excretions of the colleterial gland to the bursa copulatrix.
Second antennal segment: the third or tritocerebral segment of head.
Secondaries: the hind wings; always attached to the meta-thorax.
Secondary sexual characters: features possessed by one sex but not the other, other than the differences of the reproductive organs themselves; e.g. color, size, shape, etc.
Second clypeus: see anteclypeus.
Second costal cell: in Hymenoptera (Pack.); is the stigma.
Second inner apical: in Hymenoptera (Nort.), = media 3 (Comst), to the junction of medial cross-vein; also called sub-marginal nervure in part.
Second lateral thoracic suture: in Odonata, extends front base of secondaries to the rear of the third coxa.
Second longitudinal vein: in Diptera:= radius 2 + 3 (Comst). Second maxilla: the labium: q.v.
Second maxillary segment: the seventh or labial segment of head.