soft in the head

soft in the head idiom
Mentally deficient; also, silly, foolish. For example, He's nice enough but a bit soft in the head. The soft in this idiom, first recorded in 1775, alludes to a weakness in mental capacity.

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.