Usage: 3 forms in 3 verses
Form Translated As     In Verse(s)
σφίγξεισ you shall clasp LXX.Exod.28.28
σφίγγεται grasped by LXX.Prov.5.22
έσφιγξαν they grasped LXX.2Kgs.12.10

Liddell-Scott-Jones

σφίγγω (sphingō) to grasp G:V

σφίγγω,

[Refs 5th c.BC+]: future σφίγξω [Refs 2nd c.AD+]: aorist ἔσφιγξα [Refs 2nd c.AD+], etc.:—middle, aorist ἐσφιγξάμην [Refs 4th c.BC+]:—passive, aorist ἐσφίγχθην [Refs 5th c.BC+]: perfect ἔσφιγμαι [Refs 1st c.BC+]; infinitive ἐσφίγχθαι [Refs 4th c.BC+]: pluperfect συνέσφικτο [Refs 5th c.AD+]:—bind tight, bind fast:

__I of the person or thing bound, ἄρασσε μᾶλλον, σφίγγε [Refs 4th c.BC+]; κεκρύφαλοι σ. τεὴν τρίχ; [Refs 2nd c.AD+]shut close, [Refs 6th c.AD+]; τόκους clutch,[Refs 6th c.AD+]; σ. τὴν φράσιν straiten, abridge, [Refs 4th c.BC+]; πολλῷ χρόνῳ τὸν λόγον σφίγξαντες having severely restrained their utterance, [Refs 1st c.AD+]:—passive, ἐσφίγγετο πέπλος ζωστῆρι [Refs 3rd c.BC+] —also middle (in active sense), [Refs 4th c.BC+]
__I.2 of the thing used in binding, στραγγαλίδας ἐσφίγγετε you tied knots fast, i.e. raised all sorts of difficulties, [Refs 5th c.BC+]; σφίγγουσα τὰ πρὸς τοῖς γόνασι (i.e. σπάργανα) [Refs 3rd c.BC+]
__II bind or hold together, αἰθὴρ σ. περὶ κύκλον ἅπαντα [Refs 5th c.BC+]
__II.2 tie up in a bundle, ἀργύριον [LXX]
__II.3 tighten up, τὴν ἐκ τῆς μαλακῆς τρίψεως ἀραιότητα σ. [Refs 2nd c.AD+]; of astringents, [Refs]; σύες.. τοῖς ἄρρεσιν ἐμφερῶς ἐσφιγμέναι sows with firm flesh like boars, [Refs 2nd c.AD+]
__II.4 press together, πόδας.. κατὰ γαστέρος [Refs]

LSJ Scripture Refs: LXX.2Kgs.12.10*