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off-the-wall

American  
[awf-thuh-wawl, of-] / ˈɔf ðəˈwɔl, ˈɒf- /

adjective

Informal.

  1. markedly unconventional; bizarre; oddball.

    an unpredictable, off-the-wall personality.
off-the-wall British  

adjective

  1. slang (off the wall when postpositive) new or unexpected in an unconventional or eccentric way

    an off-the-wall approach to humour
"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
off the wall Idioms  

  1. Eccentric, unconventional, as in That idea of opening a 100-seat theater is off the wall. This expression probably originated in baseball or some other sport in which the ball can bounce off a wall in an erratic way. [Colloquial; 1960s]

Etymology

Origin of off-the-wall

First recorded in 1970–75

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.