Lexical Definition

‎πῆχυς‎ pēchys (pay'-khoos) cubit/hour ^G:N-M
of uncertain affinity

cubit.

• the fore-arm, i.e. (as a measure) a cubit

Abbott-Smith

πῆχυς, -εως, gen. pl., -ῶν (for Att. -εων, v. WH, App., 157; Thackeray, Gr., 151; Deiss., BS, 153), [in LXX chiefly and freq. for אַמָּה;]
1. the forearm (Hom.).
2. As a measure of length, a cubit: Mt 6:27, Lk 12:25, Jo 21:8, Re 21:17.†

Abbott-Smith References

Liddell-Scott-Jones

πῆχυς

(Aeolic dialect πᾶχυς [Refs 7th c.BC+], ὁ, genitive πήχεος [LXX+5th c.BC+]: genitive plural πήχεων [Refs 3rd c.BC+]; later contraction πηχῶν [Refs 5th c.BC+], Moer.p.327 P.:—forearm, from wrist to elbow, [Refs 5th c.BC+]; opposed to βραχίων, [Refs 5th c.BC+]: in Poets, generally, arm, ἀμφὶ δ᾽ ἑὸν φίλον υίὸν ἐχεύατο πήχεε λευκώ [Refs 8th c.BC+]; λευκὸν ἀντείνασα π. [Refs 5th c.BC+]; λαιὸν ἔπαιρε π. [Refs]

__2 Anatomy texts, ulna, [Refs 2nd c.AD+]
__II centrepiece, which joined the two horns of the bow, τόν ῥ᾽ [ὀϊστὸν] ἐπὶ πήχει ἑλὼν ἕλκεν νευρήν [Refs 8th c.BC+]
__III in plural, horns of the lyre, opposed to ζυγόν (the bridge), [Refs 5th c.BC+]
__III.2 also, ={ζυγόν}, crosspiece or bridge in which the horns were fitted, [Refs]
__IV in the balance, beam, [Refs]
__V as a measure of length, distance from the point of the elbow to that of the middle finger, = 6 παλασταί = 24 δάκτυλοι, [Refs 5th c.BC+]; π. ἰδιωτικός, κοινός, [Refs 5th c.BC+]; for later measurements, [Refs 2nd c.BC+]
__V.2 cubit-rule, as we say 'foot-rule', [Refs 5th c.BC+]; as epithet of Nemesis, [Refs]
__V.3 metaphorically of any small amount (compare πήχυιος), [NT]; κατὰ πῆχυν little by little, [Refs 5th c.AD+]
__VI πήχεις, οἱ, the cubits (of inundation), represented in pictures as children one cubit high playing round the Nile, [Refs 2nd c.AD+]. (Cf. Sanskrit bāhú-, Avest. bāzu- (masculine) 'arm', ONorse bógr 'shoulder'.)

_{LSJ Scripture Refs: LXX.Exod.25.9* ☩ Matt.6.27}