reckon with


Take into account, be prepared for, as in The third-party movement is a force to be reckoned with during the primaries. This usage was first recorded in 1885.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.