go under

go under idiom
  1. Suffer defeat or destruction; fail. For example, We feared the business would go under after the founder died. [Mid-1800s]
  2. Lose consciousness. For example, Ether was the first anesthetic to make patients go under quickly and completely. This usage dates from the 1930s.
  3. Submerge, sink, as in This leaky boat is about to go under.

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.

Comments
Improve this definition.
Do you have more to add? Share your linguistic knowledge or observation.
/Register to save your comments.