reckless

adjective

1. utterly unconcerned about the consequences of some action; without caution; careless (usually followed by of): to be reckless of danger.
2. characterized by or proceeding from such carelessness: reckless extravagance.

adjective

1. having or showing no regard for danger or consequences; heedless; rasha reckless driver; a reckless attempt

adj.

Old English receleas “careless, thoughtless, heedless,” earlier reccileas, from *rece, recce “care, heed,” from reccan “to care” (see reck (v.)) + -less. The same affixed form is in German ruchlos, Dutch roekeloos “wicked.” Root verb reck (Old English reccan) is passing into obscurity.