Treatise
From BiblePortal Wikipedia
Vine's Expository Dictionary of NT Words [1]
1: Λόγος (Strong'S #3056 — Noun Masculine — logos — log'-os )
"a word," denotes "a treatise or written narrative" in Acts 1:1 . See Word.
King James Dictionary [2]
TRE'ATISE, n. L. tractatus. A tract a written composition on a particular subject, in which the principles of it are discussed or explained. A treatise is of an indefinite length but it implies more form and method than an essay, and less fullness or copiousness than a system.
Webster's Dictionary [3]
(1): ( n.) Story; discourse.
(2): ( n.) A written composition on a particular subject, in which its principles are discussed or explained; a tract.