Blithe means cheerful, gay: its opposite could be morose, depressed Blithe basically means oblivion. You are perfectly confident in lala land. The opposite would be 'concerned' or 'circumspect'.
The root word of "blithely" is "blithe." "Blithe" means showing a casual and cheerful indifference that suggests a lack of concern.
Blithe means showing a casual and cheerful indifference or lack of concern. It can also refer to someone being carefree or lighthearted in their demeanor.
Perhaps you mean "blithe" which means gay, happy or cheerful
She sure is blithe spirit!
Downcast means feeling despondent. Disheartened is a synonym. Blithe is similar; it means showing a casual and cheerful indifference considered to be callous or improper." The rest of the words would be antonyms.
The fairies danced blithely in the flowering meadow.
Her blithe personality fits her just right.
Blithe Spirit was written in 1941
Albert Blithe was born on 1923-06-25.
Albert Blithe died on 1967-12-17.
She greeted everyone with a blithe smile, oblivious to the troubles around her.