Also, draw the line between. Define a limit between two groups, courses of action, or the like. For example, Legally it's important to draw a line between private and public enterprises, or We'll have to draw the line between our department's different jurisdictions. This metaphoric idiom was first recorded in 1793. Also see draw the line at.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.