The Hebrew title is Koheleth.
The Septuagint Greek version translated this, "Ecclesiastes," which means the same.
Have we ever wondered what connection of meaning there is between "Ecclesia" and "Ecclesiastes"?
The basic meaning all through is the same: Koheleth Ecclesiastes--Ecclesia: "a calling out, an assembly of called out ones."
This word also has a political aspect--it means an assembly of citizens. Throughout the Scriptures it is used to designate the assembly of the citizens of the Holy City--called-out to be such, from the generality of the world.
Specifically, Koheleth or Ecclesiastes appears to designate a member of this assembly--particularly the Chief Member--its Head, or Teacher, or Leader.
So in Ecclesiastes we clearly see a very outstanding example of what Peter terms the "Spirit of Christ in the Prophets" (1 Pet. 1:11). This gives much more meaning to the teaching of this book.