Meaning

noun the smallest whole number or a numeral representing this number

noun a single person or thing

adjective used of a single unit or thing; not two or more

originPIE word *h₁óynos Etymology tree Proto-Indo-European *ís? Proto-Indo-European *h₁óynos Proto-Germanic *ainaz Proto-West Germanic *ain Old English ān Middle English on English one From Middle English oon, on, oan, an, from Old English ān (“one”), from Proto-West Germanic *ain, from Proto-Germanic *ainaz (“one”), from Proto-Indo-European *h₁óynos (“single, one”). Doublet of an. Cognate with Scots…

Etymology from Wiktionary, CC BY-SA 3.0