Meaning

noun an argument that is conclusive

noun one of a limited class of noun modifiers that determine the referents of noun phrases

noun a determining or causal element or factor

originEtymology tree English determine Proto-Indo-European *-yósder. Proto-Italic *-āzijos Latin -āriusnom. Latin -āriusbor. Proto-Germanic *-ārijaz Proto-West Germanic *-ārī Old English -ere Middle English -ere English -er English determiner From determine + -er.

Etymology from Wiktionary, CC BY-SA 3.0