hare-brained
Wildly ill-conceived
Hare-brained describes schemes, ideas, or people as reckless and poorly thought out: a hare-brained plan to get rich quick.
The spelling hare- (like the animal) is traditional, suggesting the skittish, erratic behavior of a startled hare, though hair-brained has become common enough that some accept it.
Heedless or skin irritation
- foolhardyRecklessly bold
- irresponsibleLacking sense of duty
- heedlessCareless of consequences
- carelessInattentive, prone to mistakes
thoughtless · incautious · imprudent · ill-advised · madcap · wild · harum-scarum · devil-may-care
Wildly illogical
- idioticExtremely lacking intelligence
- nonsensicalWithout coherent meaning
- ridiculousInviting scorn through absurdity
- preposterousCompletely contrary to reason
asinine · ludicrous · inane · senseless · fatuous · daft · laughable · irrational
Acting on sudden urge
- hastyExcessively quick, ill-considered
- unthinkingLacking conscious thought
- snapSudden sharp sound
- spur-of-the-momentDone without advance planning
knee-jerk · unconsidered · rushed · precipitate · spontaneous · unplanned · impromptu · offhand
Impossible to execute
- unrealisticLacking basis in reality
- unfeasibleNot capable of execution
- half-bakedInsufficiently planned or considered
- ill-conceivedBadly thought out
quixotic · pie-in-the-sky · utopian · chimerical · fanciful · fantastical · impracticable · unviable
rash
Heedless or skin irritation
- foolhardyRecklessly bold
- irresponsibleLacking sense of duty
- heedlessCareless of consequences
careless · thoughtless · incautious · imprudent · ill-advised · madcap · wild · harum-scarum · devil-may-care · daredevil
absurd
Wildly illogical
- idioticExtremely lacking intelligence
- nonsensicalWithout coherent meaning
- ridiculousInviting scorn through absurdity
preposterous · asinine · ludicrous · inane · senseless · fatuous · daft · laughable · irrational · mindless
impetuous
Acting on sudden urge
- hastyExcessively quick, ill-considered
- unthinkingLacking conscious thought
- snapSudden sharp sound
spur-of-the-moment · knee-jerk · unconsidered · rushed · precipitate · spontaneous · unplanned · impromptu · offhand · sudden
unworkable
Impossible to execute
- unrealisticLacking basis in reality
- unfeasibleNot capable of execution
- half-bakedInsufficiently planned or considered
ill-conceived · quixotic · pie-in-the-sky · utopian · chimerical · fanciful · fantastical · impracticable · unviable · impossible