OET interlinear REV 8:11

uW Translation Notes:

Note 1 topic: figures-of-speech / explicitinfo

τὸ ὄνομα τοῦ ἀστέρος λέγεται ὁ Ἄψινθος

(Some words not found in SR-GNT: καί τό ὄνομα τοῦ ἀστέρος λέγεται ὁ Ἄψινθος Καί ἐγένετο τό τρίτον τῶν ὑδάτων εἰς ἀψίνθιον καί πολλοί τῶν ἀνθρώπων ἀπέθανον ἐκ τῶν ὑδάτων ὅτι ἐπικράνθησαν)

It might seem that this expression contains extra information that would be unnatural to express in your language. If so, you can shorten it. Alternate translation: [the name of the star is Wormwood]

Note 2 topic: translate-unknown

ὁ Ἄψινθος

¬which Wormwood

Wormwood is a woody shrub that tastes bitter. Because of its bitter taste, people in this culture believed that the shrub was poisonous. Your language may have a term for this shrub or for a similar one that you can use in your translation. You could also use a general expression. Alternate translation: [Bitter Shrub]

Note 3 topic: figures-of-speech / metonymy

ἐγένετο & ἄψινθον

became & (Some words not found in SR-GNT: καί τό ὄνομα τοῦ ἀστέρος λέγεται ὁ Ἄψινθος Καί ἐγένετο τό τρίτον τῶν ὑδάτων εἰς ἀψίνθιον καί πολλοί τῶν ἀνθρώπων ἀπέθανον ἐκ τῶν ὑδάτων ὅτι ἐπικράνθησαν)

John means by association that the water became bitter and poisonous, as if it were the bitter wormwood shrub that people in his culture believed was poisonous. Alternate translation: [became poisonous like wormwood]

Note 4 topic: figures-of-speech / genericnoun

πολλοὶ τῶν ἀνθρώπων

(Some words not found in SR-GNT: καί τό ὄνομα τοῦ ἀστέρος λέγεται ὁ Ἄψινθος Καί ἐγένετο τό τρίτον τῶν ὑδάτων εἰς ἀψίνθιον καί πολλοί τῶν ἀνθρώπων ἀπέθανον ἐκ τῶν ὑδάτων ὅτι ἐπικράνθησαν)

John is not referring to a specific group of men. He means people in general. Express this in the way that would be most natural in your language. Alternate translation: [many people]