look out for number one

• look for number one
• look out for Number One

• Audio (AU)

  (file)

look out for number one (third-person singular simple present looks out for number one, present participle looking out for number one, simple past and past participle looked out for number one)

1. (idiomatic) To act in one's own interests; to act in a manner advantageous primarily to oneself.
   • 1870, Horatio Alger, chapter 3, in Rufus and Rose:

     "I'm a poor widder, Mr. Martin, and I must look out for number one. I can't afford to keep boarders that don't pay their bills."

   • 1906, Mark Twain, What is Man?:

     Old Man: A man performs but ONE duty—the duty of contenting his spirit, the duty of making himself agreeable to himself. . . . [H]e always looks out for Number One.

• look out
• number one

• every man for himself