The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
adjective slap·hap·pi·er, slap·hap·pi·est Slang
- Dazed, silly, or incoherent from or as if from blows to the head; punch-drunk.