English

Alternative forms

• look out for Number One

Verb

look 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, Rufus and Rose, ch. 3:

     "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.

Related terms

• look out
• number one