Lexical Definition

‎ἐκψύχω‎ ekpsýchō (ek-psoo'-kho) to expire G:V
from ‎ἐκ‎ and ‎ψύχω‎

give (yield) up the ghost.

Usage: 3 forms in 5 verses
Form Translated As     In Verse(s)
ἐξέψυξεν breathed her last Acts.5.10
he breathed his last Acts.5.5Acts.12.23
εκψύξει shall expire LXX.Ezek.21.7
εκψυχούσα expiring LXX.2Sam.13.20

Abbott-Smith

ἐκ-ψύχω [in LXX: Jg 4:21 A (עוּף), Ez 21:7* (כָּהָה pi.)* ;]
to expire, breathe one's last: Ac 5:5, 10 12:23 (cf. ἐκπνέω; Cremer, 906).†

Abbott-Smith References

Book Refs
Judges 4:21
Ezekiel 21:7*
Acts 5:5 · 5:10 · 12:23

Liddell-Scott-Jones

ἐκψύχω [],

future -ξω, lose consciousness, swoon, [LXX+5th c.BC+]; give up the ghost, expire, [NT+2nd c.AD+]

__II to be short of breath, gasp, [Refs 4th c.BC+]
__III passive, to be thoroughly cooled, chilled,[Refs 1st c.AD+]

LSJ Scripture Refs: LXX.Josh.4.21Acts.5.5