v. red·lined, red·lin·ing, red·lines
1. To refuse to provide mortgages, insurance, or other goods or services to areas deemed a poor economic risk, particularly when the residents are nonwhite.
2. To reach the maximum engine speed at which an engine is designed to be safely operated: The car redlined at 80 miles per hour in fourth gear.
3. Computers To mark or highlight edited text, as with a red line, to distinguish it from unedited portions of a document.
1. To practice redlining in (an area or community), as in declining to provide mortgages.
2. To remove from operational status because of mechanical defects or the need for scheduled maintenance: redlined three fighter aircraft.
3. Computers To mark (edited text) by redlining.
n. or red line
1. A safety limit, as marked on a gauge.
2. The furthest limit of what will be tolerated: The use of chemical weapons in the conflict will cross a red line and trigger immediate intervention.
a. The red line at the center of an ice hockey rink, running parallel to the goal lines and dividing the rink in half.
b. Either of two red lines running across an ice hockey rink near the end boards, in the center of which the goal is positioned.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.