number one meaning and definition

NUMBER ONE noun

Definition of number one (noun)

1. a reference to yourself or myself etc.; `take care of number one' means to put your own interests first
2. the first or highest in an ordering or series
   • "He wanted to be the first"
   • synonyms: first
3. the first element in a countable series
   • "the first of the month"
   • synonyms: first, number 1