Mawson, C.O.S., ed. (1870–1938). Roget’s International Thesaurus. 1922.

Class VI. Words Relating to the Sentient and Moral Powers
Section II. Personal Affections
3. Prospective Affections

863. Rashness.

   NOUN:RASHNESS &c. adj.; temerity, want of caution, imprudence, indiscretion; overconfidence, presumption, audacity; precipitancy, precipitation, impetuosity; levity; foolhardihood, foolhardiness; heedlessness, thoughtlessness (inattention) [See Inattention]; carelessness (neglect) [See Neglect]; desperation; Quixotism, knight-errantry; fire eating.
  gaming, gambling; blind bargain, leap in the dark, fool’s paradise; too many eggs in one basket.
  DESPERADO, rashling [obs.], madcap, daredevil, Hotspur, Hector; scapegrace, enfant perdu [F.]; Don Quixote, knight-errant, Icarus; adventurer; dynamiter or dynamitard; fire eater, bully, bravo.
  GAMBLER, gamester (chance) [See Chance].
   VERB:BE RASH &c. adj.; stick at nothing, play a desperate game; run into danger [See Danger]; play with -fire, – edge tools; donner tête baissée [F.]; knock one’s head against a wall &c. (be unskillful) [See Unskillfulness]; kick against the pricks; rush on destruction; tempt Providence, go on a forlorn hope.
  carry too much sail, sail too near the wind, ride at single anchor, go out of one’s depth; go to sea in a sieve.
  take a leap in the dark; buy a pig in a poke; bet against a dead certainty.
  count one’s chickens before they are hatched; reckon without one’s host; catch at straws; trust to -, lean on- a broken reed.
   ADJECTIVE:RASH, incautious, indiscreet, injudicious, imprudent, improvident, temerarious; uncalculating, impulsive; heedless; careless (neglectful) [See Neglect]; without ballast, head over heels, heels over head; giddy (inattentive) [See Inattention].
  RECKLESS, wanton, wild, madcap, desperate, devil-may-care, death-defying; hot-blooded, hot-headed, hot-brained; headlong, headstrong; breakneck, foolhardy, harebrained, precipitate.
  overconfident, overweening; venture-some, venturous, adventurous, Quixotic; fire-eating.
  UNEXPECTED; off one’s guard (inexpectant) [See Inexpectation].
   ADVERB:posthaste, à corps perdu [F.], hand over head [rare], tête baissée [F.], headforemost; happen what may.
  1. Neck or nothing, the devil being in one.
  2. Non semper temeritas est felix.—Livy
  3. Paucis temeritas est bono multis malo.—Phædrus
  4. I am reckless what I do to spite the world.—Macbeth
  5. I tell thee, be not rash; a golden bridge Is for a flying enemy.—Byron