Jesus asks for the same Glory he received before something was formed.

(Joh 17:5) And now, O Father, glorify thou me with thine own self with the glory which I had with thee before the world was.

Jesus received Glory as being declared to be the Son of God before the church was formed.

(2Pe 1:17) For he received from God the Father honour and glory, when there came such a voice to him from the excellent glory, This is my beloved Son, in whom I am well pleased.

Jesus was again declared by God to be his Son at his resurrection.

(Act 13:33) God hath fulfilled the same unto us their children, in that he hath raised up Jesus again; as it is also written in the second psalm, Thou art my Son, this day have I begotten thee.

(Rom 1:4) And declared to be the Son of God with power, according to the spirit of holiness, by the resurrection from the dead:

(1Pe 1:21) Who by him do believe in God, that raised him up from the dead, and gave him glory; that your faith and hope might be in God.

World in John 17:5 is referring to the church Jesus was asking to be glorified in the same way he was before the church was formed. Thayer attempts to preserve World from Kosmos as the circle of the earth but a singular place unless referring to its content cannot be a kosmos. You are not on a world you are in a world.


G2889
κόσμος
kosmos
Thayer Definition:
1) an apt and harmonious arrangement or constitution, order, government
2) ornament, decoration, adornment, i.e. the arrangement of the stars, 'the heavenly hosts', as the ornament of the heavens. 1Pe_3:3
3) the world, the universe
4) the circle of the earth, the earth
5) the inhabitants of the earth, men, the human family
6) the ungodly multitude; the whole mass of men alienated from God, and therefore hostile to the cause of Christ
7) world affairs, the aggregate of things earthly
7a) the whole circle of earthly goods, endowments riches, advantages, pleasures, etc, which although hollow and frail and fleeting, stir desire, seduce from God and are obstacles to the cause of Christ
8) any aggregate or general collection of particulars of any sort
8a) the Gentiles as contrasted to the Jews (Rom_11:12 etc)
8b) of believers only, Joh_1:29; Joh_3:16; Joh_3:17; Joh_6:33; Joh_12:47 1Co_4:9; 2Co_5:19