Acting or done with a lack of care or caution; careless or irresponsible.
[Middle English reckeles, probably alteration (influenced by recken, to reck) of recheles, retcheles, from Old English rēcelēas; see reg- in the Appendix of Indo-European roots.]
Synonyms: reckless, rash1, foolhardy, temerarious
These adjectives mean given to or marked by unthinking boldness. Reckless suggests wild carelessness and disregard for consequences: "conceiving measures to protect the fur-bearing animals from reckless slaughter" (Gertrude Atherton).
Rash implies haste, impetuousness, and insufficient consideration: "Take calculated risks. That is quite different from being rash" (George S. Patton).
Foolhardy implies injudicious or imprudent boldness: a foolhardy attempt to wrest the gun from the mugger. Temerarious suggests reckless presumption: "this temerarious foeman who dared intervene between himself [the elephant] and his intended victim" (Edgar Rice Burroughs).
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.