Contraction of one is.

(chiefly Britain, Commonwealth of Nations except Canada, Ireland) Alternative form of no one

Obsolete spelling of only

Initialism of Office for National Statistics.

Belonging to one.

To cause to become one; to gather into a single whole; to unite.

(impersonal pronoun, indefinite) One thing (among a group of others); one member of a group.

The digit or figure 1. / (mathematics) The neutral element with respect to multiplication in a ring. / (US) A one-dollar bill. / One o'clock, either a.m. or p.m.

Used in contrast to anyone, someone or everyone: not one person; nobody.

a ketone / any similar compound containing a carbonyl functional group