"The Greek rendering of the Hebrew Koheleth, which means" Preacher. The old and traditional view of the authorship of this book attributes it to Solomon. This view can be "satisfactorily maintained, though others date it from the" Captivity. The writer represents himself implicitly as Solomon (1:12). It has been appropriately styled The Confession of King "Solomon. "The writer is a man who has sinned in giving way to" "selfishness and sensuality, who has paid the penalty of that sin" "in satiety and weariness of life, but who has through all this" "been under the discipline of a divine education, and has learned" "from it the lesson which God meant to teach him." "The writer" concludes by pointing out that the secret of a true life is that "a man should consecrate the vigour of his youth to God." The" "key-note of the book is sounded in ch. 1:2," "Vanity of vanities! saith the Preacher, Vanity of vanities! all "is vanity!" "i.e., all man's efforts to find happiness apart from God are without result.

See where Ecclesiastes occurs in the Bible...

Definition of Ecclesiastes:
"a preacher"