ar·gu·men·tum \ˌ ̷ ̷ ̷ ̷ˈmentəm\noun (pluralargumen·ta \-tə\) Etymology: Latin — more at argument : an argument, proof, or appeal to reason — used as the first term in many technical phrases designating forms both of sound and of fallacious reasoning < argumentum ad hominem > < argumentum ad captandum > — compare ad captandum, ad hominem