reckless (adj.) Look up reckless at Dictionary.com
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.