(idiomatic) At one's disposition; easily controlled by someone due to their power, affluence, charm, etc.

(informal) To get what's coming to one; to receive one's comeuppance; to suffer the undesirable consequences of one's misdeeds.

In a way that is favorable to one.

The number represented by the Arabic numeral 1; the numerical value equal to that cardinal number. / (number theory) The first positive number in the set of natural numbers.

(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.

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