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.

Of a period of time, being particular. / Being a single, unspecified thing; a; any. / Sole, only. / Whole, entire. / In agreement. / The same. / Being a preeminent example.

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

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

(Singapore, Philippines, Malaysia, transitive, colloquial); Third-person singular simple present indicative form of on

a ketone / any similar compound containing a carbonyl functional group

Belonging to one.

Contraction of one is.

(uncountable) State of being one or undivided; unity. / (countable) The product of being one or undivided.

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