off the wall
The phrase off the wall, meaning wild, crazy, or eccentric is first unambiguously attested to in F.L. Brown’s 1959 Trumbull Park:
We all said thanks in our own off-the-wall ways.
Not that off-the-wall holyroller kind of clapping.
There is an earlier use from 1953 in the title of a blues tune by Marion “Little Walter” Jacobs. But as this tune is instrumental with no lyrics, the sense of the title is ambiguous. It may be intended in the sense of odd, or it may literally mean something taken down from a wall.
The originating metaphor is unknown, but it likely refers to some sport, a racquet-sport like squash, or perhaps baseball, where a ball may literally be played off the wall, often with wild and unpredictable bounces.
(Source: Historical Dictionary of American Slang)
Copyright 1997-2017, by David Wilton