(n.) One taken at random rather than by selection; anybody. [Commonly written as two words.]

a a certain all all and some all and sundry an any one anybody anyone anything atomic aught certain each each and all each and every each one either every every one exclusive individual indivisible integral irreducible lone measured monadic monistic one one and all quantified quantitative quantitive quantized simple single singular sole solid solitary some something somewhat unanalyzable undivided uniform unique unitary whole