This is an opinion of how in English this word should be translated.
The occurrence in Matthew 9:18 compared to Mark 5:22 and Luke 8:41 are the reasons for this opinion. Note Mark 9:44, Mark 9:46 and Mark 9:48.
Matthew 2:19, ". . . But when Herod
dies, behold, an angel of the Lord appeareth in a dream to Joseph in Egypt, . . ."
Matthew 9:18, ". . . While he spake these things unto them, behold, there came a certain ruler, and worshipped him, saying, My daughter is even now
dies: but come and lay thy hand upon her, and she shall live. . . ."
The two parallel passages do not use this word.
Mark 5:22-23, ". . . And, behold, there cometh one of the rulers of the synagogue, Jairus by name; and when he saw him, he fell at his feet, And besought him greatly, saying, My little daughter lieth at the point of death:
I pray thee, come and lay thy hands on her, that she may be healed; and she shall live. . . ."
Luke 8:41-42, ". . . And, behold, there came a man named Jairus, and he was a ruler of the synagogue: and he fell down at Jesus' feet, and besought him that he would come into his house:
For he had one only daughter, about twelve years of age, and she lay a dying. But as he went the people thronged him. . . ."
Matthew 15:4, ". . . For God commanded, saying, Honour thy father and mother: and, He that curseth father or mother,
let him die the death. . . ."
Mark 7:10, ". . . For Moses said, Honour thy father and thy mother; and, Whoso curseth father or mother,
let him die the death: . . ."
Matthew 22:25, ". . . Now there were with us seven brethren: and the first, when he had married a wife,
dies, and, having no issue, left his wife unto his brother: . . ."
Mark 9:44, ". . . Where their worm
dies not, and the fire is not quenched. . . ."
Mark 9:46, ". . . Where their worm
dies not, and the fire is not quenched. . . ."
Mark 9:48, ". . . Where their worm
dies not, and the fire is not quenched. . . ."
Luke 7:2, ". . . And a certain centurion's servant, who was dear unto him, was sick, and ready
to die. . . ."
Acts of the Apostles 2:29, ". . . Men
and brethren, let me freely speak unto you of the patriarch David, that
he both
dies and was buried, and his sepulchre is with us unto this day. . . ."
Acts of the Apostles 7:15, ". . . So Jacob went down into Egypt, and
dies, he, and our fathers, . . ."
Hebrews 11:22, ". . . By faith Joseph, when he
dies, made mention of the departing of the children of Israel; and gave commandment concerning his bones. . . ."