Lexical Definition

‎πύλη‎ pýlē (poo'-lay) gate ^G:N-F
apparently a primary word

gate.

• a gate, i.e. the leaf or wing of a folding entrance (literally or figuratively)

Abbott-Smith

πύλη, -ης, ἡ, [in LXX chiefly and very freq. for שַׁעַר sometimes for דֶּלֶת, פֶּתַח;]
a gate: Lk 7:12, Ac 9:24 12:10 16:13, He 13:12; ἡ Ὡραία Π. τ. ἱεροῦ, Ac 3:10. Metaph., Mt 7:13, 14; πύλαι ᾅδου (Wi 16:13, III Mac 5:51, and cf. κλεῖς ᾅδου, Re 1:18): Mt 16:18.†

Abbott-Smith References

Liddell-Scott-Jones

πύλη [ῠ], ἡ,

properly one wing of a pair of double gates, ὀλίγον τι παρακλίναντες τὴν ἑτέρην π. [Refs 5th c.BC+]: mostly in plural, gates of a town (whereas θύρα = house-door), Σκαιαὶ π. [Refs 8th c.BC+]; ἄνεσάν τε π. καὶ ἀπῶσαν ὀχῆας[Refs 5th c.BC+]: plural of several gates, [Refs 4th c.BC+]; ἐν πύλαις in or at the gates, [Refs]; ἐπὶ ταῖς πύλαισιν, οὗ τὸ τάριχος ὤνιον [Refs 5th c.BC+]

__2 in Trag. sometimes of the house-door, δωμάτων πύλαι [Refs 4th c.BC+]; γυναικείους π. gate or door leading to the women's apartments,[Refs 5th c.BC+]: also in singular,[Refs]; of the door of a tent, [πύλης ἄναξ θυρωρέ [prev. author] “fragment” 775. ">Refs]
__3 πύλαι Ἀΐδαο the gates of the nether world, periphrasticfor hell, [NT+8th c.BC+]
__4 custom-house, [Refs 2nd c.BC+]; τετελώνηται διὰ πύλης has paid the customs, [Refs 3rd c.AD+]; τὸ σύμβολον τῆς ἱερᾶς Συηνιτικῆς π. [Refs 1st c.BC+]; μισθωταὶ ἱερᾶς π. Σοήνης [Refs 2nd c.AD+]
__II generally, entrance, orifice, ἀμφὶ πύλας ἰσθμοῖο [Refs 5th c.BC+]; ἡλίου πύλαι, [Refs 4th c.BC+]; portal fissure of the liver, π. καὶ δοχαὶ χολῆς [Refs 5th c.BC+]; portal vein of the liver, [Refs 2nd c.AD+]
__II.b plural, of the carceres in the circus, [Refs 2nd c.AD+]
__II.c metaphorically, πύλας ὕμνων ἀναπιτνάμεν [Refs 5th c.BC+]
__II.2 entrance into a country through mountains, pass, [Refs 5th c.BC+], the Gates of Greece, [Refs]: of other passes, π. τῆς Κιλικίας καὶ τῆς Συρίας [Refs 5th c.BC+]; αἱ Κάσπιαι π. [Refs 1st c.BC+]; Ἀμανίδες π. [Refs 2nd c.AD+]: these passes were sometimes really barred by gates, [Refs 5th c.BC+]; Πέλοπος νάσου θεόδματοι π[Refs 1st c.AD+]
__II.3 of narrow straits, by which one enters a broad sea, Πύλαι Γαδειρίδες the [Refs 5th c.BC+]; ἐπ᾽ αὐταῖς στενοπόροις λίμνης π., of the Thracian Bosporus, [Refs 4th c.BC+]; ἐν πύλαις, of the Euripus, [Refs 5th c.BC+]

_{LSJ Scripture Refs: Matt.16.18}