Example : Foolhardy enough to try to seize the gun from the hijacker.
Became the fiercest and most reckless of partisans.
A reckless driver.
A rash attempt to climb Mount Everest.

Synonyms : foolhardy, heady, rash

Example : The heedless generosity and the spasmodic extravagance of persons used to large fortunes.
Reckless squandering of public funds.

Synonyms : heedless