°A numerical value equal to 1; the first number in the set of natural numbers (especially in number theory); the cardinality of the smallest nonempty set.
"There is only one Earth."
°The ordinality of an element which has no predecessor, usually called first or number one.
°Of a period of time, being particular; as, one morning, one year.
°Being a single, unspecified thing; a; any.
synonyms: you, they, !, 1 more» , eleven