characterized by careless unconcern; "the heedless generosity and the spasmodic extravagance of persons used to large fortunes"- Edith Wharton; "reckless squandering of public funds"
marked by or paying little heed or attention; "We have always known that heedless self-interest was bad morals; we know now that it is bad economics"--Franklin D. Roosevelt; "heedless of danger"; "heedless of the child's crying"
showing the cunning or ingenuity or wickedness typical of a devil; "devilish schemes"; "the cold calculation and diabolic art of some statesmen"; "the diabolical expression on his face"; "a mephistophelian glint in his eye"
playful in an appealingly bold way; "a roguish grin"