Quick Definition
ἐκπετάννυμι v. I spread or stretch out
Strong's Definition
to fly out, i.e. (by analogy) to extend
Derivation: from G1537 (ἐκ) and a form of G4072 (πέτομαι);
KJV Usage: stretch forth
UBS Dictionary of the Greek New Testament
verb | aor. ἐξεπέτασα | πετάννυμι (stretch) · πέτομαι
16.19 · Non-Linear Movement
to stretch out, to extend, to reach out to cause an object to extend in space (for example, by becoming straight, unfolded, or uncoiled)
1 With ἐκτείνω and ἐκπετάννυμι there is a type of movement in space, but only a movement of an extremity, not of the base from which the extension takes place. There is a sense in which the occurrence of hand with ἐκτείνω and ἐκπετάννυμι involves the motion of a body part (see Domain 18 Attachment), but since the same terms may be used not only of body parts but of any object which may be extended, it seems more satisfactory to classify all of these related meanings together.
UBS Dictionary of the Greek New Testament © United Bible Societies, licensed CC BY-SA 4.0.
Thayer's Greek Lexicon
Mounce Concise Greek Dictionary
ἐκπετάννυμι ekpetannymi 1x
pluperfect, ἐκπεπετάκειν, to stretch forth, expand, extend, Rom. 10:21*
Abbott-Smith Greek Lexicon
ἐκ-πετάννυμι
[in LXX chiefly for פָּרַשׂ, as Is 65:2 (hithp.) ;]
to spread out (as a sail), stretch forth: Ro 10:21(LXX).†
Moulton & Milligan — Vocabulary of the Greek NT
ἐκπετάννυμι. For this NT ἅπ. εἰρ. (Rom 107! from Isai 652) = ‘‘ spread out,”’ the ἐκ showing the action of the verb carried as far as it will go (cf. ἐκτείνω), cf. Kazbel 7792— Οὔριον ἐκ πρύμνης τις ὁδηγητῆρα καλείτω Ζῆνα κατὰ προτόνων ἱστίον ἐκπετάσας. See Anz Subsidia, p. 286.
Liddell-Scott-Jones — Greek-English Lexicon
ἐκπετάζω (ekpetazō) — to extend. ἐκπετάζω, ={ἐκπετάννυμι}, [LXX]