number one

noun

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

adjective

4. of the highest in quality, status, importance, etc.; first-rate: a number one performance.
5. first in rank, order, or prestige: the number one book on the bestseller list.

Idioms

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

noun

1. the first in a series or sequence
2. an informal phrase for oneself, myself to look after number one
3. informal the most important person; leader, chiefhe’s number one in the organization
4. informal the bestselling pop record in any one week
5. euphemistic the act or an instance of urination
6. a haircut in which the hair is cut very close to the head with an electric shaver

adjective

7. first in importance, urgency, quality, etcnumber one priority
8. informal (of a pop record) having reached the top of the charts