Be ambitious, as in There's no point in moving to a place the same size; we have to think big and plan for expansion. [Colloquial; mid-1900s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
How to use think big in a sentence
The Kardashians Go High Fashion for Annual Christmas Card: When it comes to the family holiday card, the Kardashians think big.The Kardashians Go High Fashion for Annual Christmas Card; First Look at Kate Moss's 'Playboy' Cover | The Fashion Beast Team | December 2, 2013 | THE DAILY BEAST
But no matter what state you look in, think big and significant places.Clues for Finding Forrest Fenn’s Buried Treasure, Part 2 | Tony Doukopil | March 3, 2013 | THE DAILY BEAST
But I think big government conservatism is a failed experiment.
Come and look at my picture, little Jack, and see if you think big Jack knows how to paint.'Christie, the King's Servant | Mrs. O. F. Walton
When we have succeeded in doing something big they will come to us and if we think big things we are likely to do them.Laugh and Live | Douglas Fairbanks