Dictionary Home » The American Heritage Dictionary of Idioms » let down

let down

let down idiom

Cause to descend, lower, as in They let down the sails. [Mid-1100s]
Also, let up. Slacken, abate, as in Sales are letting down in this quarter, or They didn't let up in their efforts until the end. The first term dates from the mid-1800s, the variant from the late 1700s.
See let someone down. Also see let one's hair down.

The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.