• Being a single unit, or entire being or thing, and no more; not multifold; single; individual. • Denoting a person or thing conceived or spoken of indefinitely; a certain. "I am the sister of one Claudio" [Shak.], that is, of a certain man named Claudio. • Pointing out a contrast, or denoting a particular thing or person different from some other specified; -- used as a correlative adjective, with or without the. • Closely bound together; undivided; united; constituting a whole. • Single in kind; the same; a common. • Single; inmarried. • A single unit; as, one is the base of all numbers. • A symbol representing a unit, as 1, or i. • A single person or thing. • Any person, indefinitely; a person or body; as, what one would have well done, one should do one's self. • To cause to become one; to gather into a single whole; to unite; to assimilite.