The headword, with oxytone accent, is a later Greek variant of the proparoxytone (cf. Smyth, 157) form attested in, for instance, Homer, Iliad 23.327 (web address 1); see LSJ s.v. o)/rguia (the length of outstretched arms or approximately six feet). See also omicron 522, omicron 523.
[1] The headword is similarly glossed in ps.-Herodian, Partitiones 102.5, and Hesychius omicron1122 s.v. o)rguia/.
[2] Greek Anthology 6.223.2-3 (attributed to Antipater of Sidon); see Gow and Page (vol. I, 28) and further extracts from this epigram at alpha 1732, gamma 456, epsilon 3049, pi 1426, and xi 15. At eight fathoms in length, the sea-scolopendra or sea-millipede found by the fisherman Hermonax of the epigram probably represents a fantastic exaggeration (cf. Aristotle, History of Animals 505b14-5, where the real size of sea millipedes is reported). However unlikely, the report might also have arisen from a mistaken identification of tattered animal remains; see Gow and Page (vol. II, 74-5), for possible sea creatures of sufficient size to inspire such an error.