Praise be to Allah, the Lord of the World; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
Please, read Fatwa No: 82061 and 82052 for information about the descent of Jesus on earth and the coming of al-Dajjal (Anti-Christ).
As for the meaning of the word Messiah, scholars differ about using such a word both for Jesus and al-Dajjal.
The word Messiah is used with the name of Prophet Jesus (Alaihi al-Salaam) to mean:
1) One does not live in some house, one who goes from one place to another.
2) One who cures sick people by rubbing over them.
3) The anointed one.
4) One whose beauty is plain.
5) One who is sinless.
The same word (i.e. Messiah) is used with the name of al-Dajjal to mean:
1) The one-eyed.
2) The one who roams the earth, except Makka, al-Madinah and Jerusalem.
N.B.:- Please, consult Tafsir al-Qurtubi volume 4, Page-89.
The statement: "al-Dajjal has only one eye" is recorded in a Hadith in al-Bukhari.
Allah knows best.