number one

Adjective

• First; foremost; best, often used after its headword.

Noun

• The most important person, the one who is in charge.
• Someone who is top of a ranking, who is ranked first.
• Oneself, being considered foremost, as by an egoist.
• Urine; urination.
• The single that has sold the most in a given period.
• The main goalkeeper of a team, so-called because they wear the number 1 on the back of their kit.
• The batsman who opens the batting.
• A first lieutenant.
• A large town where theatrical performances may expect to achieve success.