Quick Definition
I breathe my last, expire
Strong's Definition
to expire
Derivation: from G1537 (ἐκ) and G4154 (πνέω);
KJV Usage: give up the ghost
Thayer's Greek Lexicon
ἐκπνέω: 1 aorist ἐξέπνευσα; to breathe out, breathe out one's life, breathe one's last, expire: Mar_15:37; Mar_15:39; Luk_23:46, and often in Greek writings, both without an object (from (Sophocles Aj. 1026) Euripides down), and with βίον or ψυχήν added (from Aeschylus down).
Mounce Concise Greek Dictionary
ἐκπνέω ekpneō 3x
to breathe out; to expire, die, Mar_15:37 ; Mar_15:39 ; Luk_23:46
Abbott-Smith Greek Lexicon
* ἐκ -πνέω , -ῶ , to breathe out; sc . βίον , ψυχήν (expressed in cl ., Ζsch ., al. ; cf. LS , s.v. ), to breathe one's last, expire: Mar_15:37 ; Mar_15:39 Luk_23:46 . For force of aorist, v. Swete , Mar_15:37 .†
Liddell-Scott — Intermediate Greek Lexicon
ἐκπνέω epic -πνείω fut. -πνεύσομαι or -οῦμαι "to breathe out or forth", Plat. ; κεραυνὸς ἐκπνέων φλόγα Aesch. βίον ἐκπν. "to breathe one's last, expire", id=Aesch. , Eur. ; also, ἐκπν. θυμόν, ψυχήν id=Eur. absol. "to cease blowing, to become calm", id=Eur. "to blow outwards", of wind, Hdt. , Thuc. : "to burst out", Soph.
STEPBible — Tyndale Abridged Greek Lexicon
ἐκ-πνέω, -ῶ,
to breathe out; sc. βίον, ψυχήν (expressed in cl., Æsch., al.; cf. LS, see word), to breathe one's last, expire: Mrk.15:37, 39 Luk.23:46. For force of aorist, see Swete, Mrk.15:37.†
(AS)