Idioms and Phrases with think big
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.