What does argument mean?
The definition of argument
Ar”gu*ment, n.
Etym: [F. argument, L. argumentum, fr. arguere to argue.]

1 Proof; evidence. [Obs.] There is.. no more palpable and convincing argument of the existence of a Deity. Ray. Why, then, is it made a badge of wit and an argument of parts for a man to commence atheist, and to cast off all belief of providence, all awe and reverence for religion South.
2 A reason or reasons offered in proof, to induce belief, or convince the mind; reasoning expressed in words; as, an argument about, concerning, or regarding a proposition, for or in favor of it, or against it.
3 A process of reasoning, or a controversy made up of rational proofs; argumentation; discussion; disputation. The argument is about things, but names. Locke.
4 The subject matter of a discourse, writing, or artistic representation; theme or topic; also, an abstract or summary, as of the contents of a book, chapter, poem. You and love are still my argument. Shak. The abstract or argument of the piece. Jeffrey. [Shields] with boastful argument portrayed. Milton.
5 Matter for question; business in hand. [Obs.] Sheathed their swords for lack of argument. Shak.
6 (Astron.)
The quantity on which another quantity in a table depends; as, the altitude is the argument of the refraction.
7 (Math.)
The independent variable upon whose value that of a function depends. Brande & C.

Ar”gu*ment, v. i.
Etym: [L. argumentari.]

To make an argument; to argue. [Obs.] Gower.