Roget's Thesaurus of English Words and Phrases by Peter Mark Roget

imprudence, indiscretion; overconfidence, presumption, audacity. precipitancy, precipitation; impetuosity; levity; foolhardihood†, foolhardiness; heedlessness, thoughtlessness &c (inattention) 458; carelessness &c (neglect) 460; desperation; Quixotism, knight-errantry; fire eating. gaming, gambling; blind bargain, leap in the dark, leap of faith, fool's paradise; too many eggs in one basket. desperado, rashling†, madcap, daredevil, Hotspur, fire eater, bully, bravo, Hector, scapegrace, enfant perdu [Fr.]; Don Quixote, knight-errant, Icarus; adventurer; gambler, gamester; dynamitard†; boomer [U.S.]. V. be rash &c adj.; stick at nothing, play a desperate game; run into danger &c 665; play with fire, play with edge tools. carry too much sail, sail too near the wind, ride at single anchor, go out of one's depth. take a leap in the dark, buy a pig in a poke. donner tete baissee [Fr.]; knock, one's bead against a wall &c (be unskillful) 699; rush on destruction; kick against the pricks, tempt Providence, go on a forlorn hope, go on a fool's errand. reckon one's chickens before they are hatched, count one's chickens before they are hatched, reckon without one's host; catch at straws; trust to a broken reed, lean on a broken reed. Adj. rash, incautious, indiscreet; imprudent, improvident, temerarious; uncalculating†; heedless; careless &c (neglectful) 460; without ballast, heels over head, head over heels; giddy &c (inattentive) 458; wanton, reckless, wild, madcap; desperate, devil-may-care. hot-blooded, hotheaded, hotbrained†; headlong, headstrong; breakneck; foolhardy; harebrained; precipitate, impulsive. overconfident, overweening; venturesome, venturous; adventurous, Quixotic, fire eating, cavalier; janty†, jaunty, free and easy. off one's guard &c (inexpectant) 508 [Obs.]. Adv. post haste, a corps perdu [Fr.], hand over head, tete baissee [Fr.], headforemost†; happen what may, come what may. Phr. neck or nothing, the devil being in one; non semper temeritas est felix [Lat.] [Livy]; paucis temeritas est bono multis malo [Lat.] [Phaedrus].