A superlative probably from echo (in the sense of contiguity); farthest, final (of place or time) -- ends of, last, latter end, lowest, uttermost.

see GREEK echo

1. joined to nouns: τόπος, the last in a series of places (A. V. lowest), Luke 14:9f; in a temporal succession, the last: ἔσχατος ἐχθρός, that remains after the rest have been conquered, 1 Corinthians 15:26; κοδράντης, that remains when the rest have one after another been spent, Matthew 5:26; so λεπτόν, Luke 12:59; ἡ ἐσχάτῃ σάλπιγξ, the trumpet after which no other will sound, 1 Corinthians 15:52, cf. Meyer ad loc.; αἱ ἔσχαται πληγαί, Revelation 15:1; Revelation 21:9; ἡ ἐσχάτῃ ἡμέρα τῆς ἑορτῆς, John 7:37. When two are contrasted it is equivalent to the latter, opposed to ὁ πρῶτος the former (Deuteronomy 24:1-4): thus τά ἔργα (opposed to τῶν πρώτων), Revelation 2:19; ἡ πλάνη, Matthew 27:64 (where the meaning is, 'lest the latter deception, caused by the false story of his resurrection, do more harm than the former, which was about to produce belief in a false Messiah'); ὁ ἔσχατος Ἀδάμ, the latter Adam, i. e. the Messiah (see Ἀδάμ, 1), 1 Corinthians 15:45. ἡ ἐσχάτῃ ἡμέρα, the last day (of all days), denotes that with which the present age (הַזֶּה הָעולָם, see αἰών, 3) which precedes the times of the Messiah or the glorious return of Christ from heaven will be closed: John 6:39f, 44 (); . of the time nearest the return of Christ from heaven and the consummation of the divine kingdom, the following phrases are used: ἐσχάτῃ ὥρα, 1 John 2:18; ἐν καιρῷ ἐσχάτῳ 1 Peter 1:5; ἐν ἐσχάτῳ χρόνῳ, Jude 1:18 Rec., ἐπ' ἐσχάτου χρόνου Jude 1:10. Tr WH; ἐν ἐσχάταις ἡμέραις, Acts 2:17; James 5:3; 2 Timothy 3:1; for other phrases of the sort see 2 a. below; ἐπ' ἐσχάτων τῶν χρόνων, 1 Peter 1:20 R G, see below.

2. ὁ, ἡ, τό ἔσχατον absolutely or with the genitive,

a. of time: οἱ ἔσχατοι, who had come to work last, Matthew 20:8, 12,(14); the meaning of the saying ἔσονται πρῶτοι ἔσχατοι καί ἔσχατοι πρῶτοι is not always the same: in Luke 13:30 it signifies, those who were last invited to enter the divine kingdom will be first to enter when the opportunity comes, i. e. they will be admitted forthwith, while others, and those too who were first among the invited, will be shut out then as coming too late; in Matthew 19:30; Matthew 20:16 it means, the same portion in the future kingdom of God will through his goodness be assigned to those invited last as to those invited first, although the latter may think they deserve something better; cf. Mark 10:31. ὁ πρῶτος καί ὁ ἔσχατος i. e. the eternal, Revelation 1:11 Rec., ; . ἔσχατος as a predicate joined to a verb adverbially (cf. Winer's Grammar, 131 (124); § 54, 2): Mark 12:6; ἐσχάτῃ (R G; but see below) πάντων ἀπέθανε, Mark 12:22. ἔσχατον, ἔσχατα, used substantively (cf. Buttmann, 94 (82) § 125, 6) in phrases, of the time immediately preceding Christ's return from heaven and the consummation of the divine kingdom: ἐπ' ἐσχάτου or ἐσχάτων τῶν ἡμερῶν, Hebrews 1:2 (1); 2 Peter 3:3 (the Epistle of Barnabas 16, 5 [ET]); τῶν χρόνων, 1 Peter 1:20; ἐπ' ἐσχάτου τοῦ χρόνου, Jude 1:18 L T (see 1 above, and ἐπί, A. II. at the end), cf. Riehm, Lehrbegr. d. Hebrärbriefes, p. 205f τά ἔσχατα with the genitive of person the last state of one: Matthew 12:45; Luke 11:26; 2 Peter 2:20 (but without the genitive of person). Neuter ἔσχατον, adverb, lastly: (with the genitive of person, Mark 12:22 L T Tr WH); 1 Corinthians 15:8.

b. of space: τό ἔσχατον τῆς γῆς, the uttermost part, the end, of the earth, Acts 1:8; Acts 13:47.

c. of rank, grade of worth, last i. e. lowest: Mark 9:35; John 8:9 Rec.; 1 Corinthians 4:9.