be on to


1

Be aware of or have information about, as in They can't pull that trick again; we're on to them now. [Colloquial; second half of 1800s]

2

Discover something important or profitable, as in The researchers claim they are really on to something big. [Colloquial; mid-1900s]

QUIZZES

WHO SAID IT: A QUIZ ON PRESIDENTIAL WIT AND WISDOM

Think you know your presidents? Take this quiz and see if you can match the style, wit, and ideology of these memorable lines to the right POTUS.
Question 1 of 9
“I do believe that the buck stops here, that I cannot rely upon public opinion polls to tell me what is right. I do believe that right makes might and that if I am wrong, 10 angels swearing I was right would make no difference.”
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.