(US, shoptalk) Wasting time, or exertion, on some absurd venture. thing.
A movement that is viewed as senseless, or dumb, or time-squandering. thing.
A movement that might be thought of as unlawful,
sketchy, or a bad habit, yet entirely not felonious.
Foolishness' means accomplishing something naughty.
"The organization terminated its bookkeeper since there was some foolishness
happening with the records." "The kids will get up
to horseplay on the off chance that we don't watch out for them."