Entomology definition of Plecoptera or Plectoptera: plaited winged: an ordinal
term applied to net-veined insects in which the secondaries are
longitudinally folded beneath primaries; mouth mandibulate; body
loosely jointed; prothorax free; metamorphosis incomplete: the
term Plecoptera was used by Brauer for Perlidae; Plectoptera by
Packard for the Ephemerida: there has been some confusion since,
and both have been used in the Brauer sense.