nonsense, ridiculous idea
● Madness
● Silliness
● Craziness
● Absurdity
● Indiscretion
● Foolishness
● Recklessness
● Idiocy
● Stupidity
● Lunacy
● Inanity
● Fatuity
● Vice
● Unsoundness
● Triviality
● Imprudence
● Imbecility
● Impracticality
● Irrationality
● Senselessness
● Rashness
● Preposterousness
● Inadvisability
● Obliquity
● Dottiness
● Dumb thing to do
● Dumb trick
● Witlessness
● Understanding
● Seriousness
● Judgment
● Intelligence
● Carefulness
● Care
● Sense
● Wisdom
● Knowledge
● Daftnesses
● Flakiness