blithe
Definitions
Showing a casual and cheerful indifference considered to be callous or improper.
Happy or carefree in disposition; lighthearted.
Examples
She maintained a blithe indifference to the criticism directed at her work.
His blithe disregard for the rules eventually led to his dismissal from the company.
The children played with a blithe spirit, completely unaware of the troubles surrounding them.
Synonyms
carefree cheerful lighthearted joyous happy breezy insouciant