number one

See synonyms for number one on
  1. oneself, especially one's own well-being or interests: to look out for number one.

  2. a person, company, etc., that is first in rank, order, or prestige: Our team is number one.

  1. urination: used especially by or with reference to children.

  1. of the highest in quality, status, importance, etc.; first-rate: a number one performance.

  2. first in rank, order, or prestige: the number one book on the bestseller list.

Idioms about number one

  1. make / do / go number one, Informal. to urinate: used especially by or with reference to children.

Origin of number one

First recorded in 1830–40

Words Nearby number one Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use number one in a sentence

British Dictionary definitions for number one

number one

  1. the first in a series or sequence

  2. an informal phrase for oneself, myself to look after number one

  1. informal the most important person; leader, chief: he's number one in the organization

  2. informal the bestselling pop record in any one week

  3. euphemistic the act or an instance of urination

  4. a haircut in which the hair is cut very close to the head with an electric shaver

  1. first in importance, urgency, quality, etc: number one priority

  2. informal (of a pop record) having reached the top of the charts

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012