1. (informal) oneself, especially one's own interests 
2. (informal) the most important of a group of people

Derived forms: numero unos

• spectrogram
• spectrograph
• spectrographic
• gradable opposition
• gradate
• gradation
• gradational
• gradatory
• grade
• grade crossing
• grade insignia
• grade point
• grade point average
• grade school
• grade separation
• grade-appropriate
• grade-constructed
• graded
• grader
• gradient
• grading
• gradual
• gradualism
• graduality
• gradually