Lacking in caution.

Roget 863: rash, incautious, indiscreet; imprudent, improvident, temerarious; uncalculating^†; heedless; careless etc. (neglectful) 460; without ballast, heels over head, head over heels; giddy etc. (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 etc. (inexpectant) 508^†.    ... show more

Carelessly failing to exercise proper caution.

Polish: nieostrożny, niebaczny