number one

Noun (3)

1. a reference to yourself or myself etc.; ‘take care of number one’ means to put your own interests firstType of self
2. the first or highest in an ordering or series“He wanted to be the first”Synonyms: firstType of rankKinds former
3. the first element in a countable series“the first of the month”Synonyms: firstnumber 1Type of ordinal number, ordinal