A.threshold, esp. threshold of a house, in Hom. χάλκεος οὐδός (as in Hes.Th.811), Od.7.83,89; also “λάϊνος” Il.9.404, Od. 8.80, Parm.1.12; “μέλινος” Od.17.339; “δρύϊνος” 21.43; “μέγας” Hes.Th. 749.
2. generally, threshold, entrance to any place, “ἐπὶ προθύροις Ὀδυσῆος, οὐδοῦ ἐπ᾽ αὐλείου” Od.1.104; to the nether world, Il.8.15; “χαλκόπους ὀδός” S.OC57, cf. 1590: in pl., perh. lintel, Theoc.23.50 (dub. l., ὀόδων cod.).
3. metaph., ἐπὶ γήραος οὐδῷ on the threshold which is old age, i.e. perh., on the threshold that leads from life to death (so οὐδὸς βιότου the end of life, Q.S.10.426), Il.22.60, Od.15.348, Hes.Op.331, Hdt.3.14, cf. Pl.R.328e; “ἐπὶ γήρως ὀδῷ” Lycurg., Hyp., and Men. ll. cc.; “μέχρι γήραος οὐδοῦ” Ps.-Phoc.230; “γήραος οὐδὸν ἱκέσθαι” Od.23.212, cf. 15.246.—Poet. word, used by Arist. Metaph.1042b19, Plu. TG17, and Luc.Dom.18, al., in the form οὐδός, which is Ion., cf. Hp.Art.78, GDI5601a（Ephesus), IG11(2).158 A 69 (Delos, iii B. C.), and is used later as gloss on βηλός, AB224 (so ὀδός in 225 and Hsch. s.v. ὀρρόβηλος). (The forms οὐδός ὠδός ὀδός point to Ο᾿δϝός.)