From BiblePortal Wikipedia

Vine's Expository Dictionary of NT Words [1]

A — 1: Ἔξοδος (Strong'S #1841 — Noun Masculine — exodos — ex'-od-os )

(Eng., "exodus"), lit. signifies "a way out" (ex, "out," hodos, "a way"); hence, "a departure," especially from life, "a decease;" in  Luke 9:31 , of the Lord's death, "which He was about to accomplish;" in  2—Peter 1:15 , of Peter's death (marg., "departure" in each case); "departure" in  Hebrews 11:22 , RV. See Departure.

B — 1: Τελευτάω (Strong'S #5053 — Verb — teleutao — tel-yoo-tah'-o )

lit., "to end," is used intransitively and translated "deceased" in  Matthew 22:25 . See Death , A, No. 3, DIE.

Hastings' Dictionary of the Bible [2]

Decease . The Gr. word exodos (‘exodus,’ ‘outgoing’) is translated ‘decease’ in   Luke 9:31 and   2 Peter 1:15 , the meaning being departure out of the world. In this sense the Gr. word is used also in Wis 3:2; Wis 7:6 , Sir 38:23 . The opposite, eisodos , is used of the ‘coming’ of Christ. The only other occurrence of the Gr. exodos in NT is in   Hebrews 11:22 , of the Exodus from Egypt (AV [Note: Authorized Version.] and RV [Note: Revised Version.] ‘departure’).

Webster's Dictionary [3]

(1): ( n.) Departure, especially departure from this life; death.

(2): ( v. i.) To depart from this life; to die; to pass away.

King James Dictionary [4]

DECE'ASE, n. L. to depart or to withdraw. Literally, departure hence, departure from this life death applied to human beings only.