Heedless of or indifferent to the consequences of one's actions; lacking in prudence or caution; willing or liable to take risks; rash…

Rash, quick to anger.

Reckless, heedless. Cf. un-, prefix1 affix 10a. Obsolete.

Characterized by excessive speed or urgency; rash; = hasty, adj. 4.

Of a person: rash, impetuous, reckless; rough, crude. Also: sturdy in old age.

Of headstrong courage; impetuous; precipitate, rash; in later use (passing into the next sense), Aggressive, contentious. Obsolete.

Unruly; inconsiderate, rash or impetuous.

Rash, reckless; = temerarious, adj. 1.

Rash, foolhardy; = temerarious, adj. 1.

Hasty, impetuous; acting or speaking without due consideration or regard for consequences; reckless, thoughtless, foolhardy.

Characterized by temerity; unreasonably adventurous; reckless, heedless, rash.

Having or showing no more ‘brains’ or sense than a hare; heedless, reckless; rash, wild, mad. Of persons, their actions, etc.

= temerarious, adj. 1.

attributive or adj.= hare-brained, adj.

= hotspur, adj.

Too rash; excessively rash.

Of a fiery temperament; hasty, rash.

Mad, crazy; idiotic, wildly impulsive or extravagant; bizarre, zany.

Of persons: Heedless, careless, imprudent; = reckless, adj.

Of or relating to Phaethon; = Phaetonic adj. at phaeton, n. derivatives.

that has been deprived of discernment or mental perception as a result of (excessive) enthusiasm or zeal; (also) characterized by this.

Of or relating to Phaethon; = Phaetonic adj. at phaeton, n. derivatives.

= unresponsible, adj. (in various senses).

= Phaetonic adj. at phaeton, n. derivatives.

Usually in predicative use, with on, upon, or infinitive. Determined to achieve something at all costs; passionately or recklessly intent. Cf. bend…

Reckless, careless, heedless in action; wild rash. (Of persons and their actions.)

Originally: that cannot be relied on; unreliable. Later more usually: reckless, imprudent, irresponsible.

Esp. of a course of action: disastrously damaging to oneself or one's interests; dangerous and ill-advised.

Strong-willed, headstrong; quarrelsome.

dialect. Of a horse: Skittish, unmanageable; high-mettled. Hence (?) of persons (see quot. 1855).

Cheerfully reckless; carefree.

Having a massive head, broadheaded; figurative blindly impetuous, blockheaded.

Characterized by a devil-may-care attitude; cheerfully reckless.

Full of temerity; rash.

figurative and in extended use. Reckless, dangerous; hazardous and potentially self-destructive.