Off-the-wall

Alternative forms

• off the wall

Origin

Perhaps from baseball or other games played with a ball, alluding to unpredictable bounces.

Full definition of off-the-wall

Adjective

1. (idiomatic) Wildly unconventional; bizarre; absurd.What kind of a harebrained, off-the-wall idea is that?She is a very off-the-wall character.
2. (idiomatic) Greatly inappropriate.His behaviour today is off-the-wall.