recklessyoudaoicibaDictYouDict[reckless 词源字典]
reckless: [OE] The reck- of reckless is the same word as the now virtually obsolete verb reck ‘care’. It is not clear where this ultimately came from, but the compound reckless itself evidently goes back to the prehistoric West Germanic period, for it also occurs in German (ruchlos) and Dutch (roekeloos).
[reckless etymology, reckless origin, 英语词源]
reckless (adj.)youdaoicibaDictYouDict
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.