IPA: /ˈblaɪðli/
KK: /ˈblaɪðli/
In a happy and carefree way, without worrying about the consequences.
She blithely ignored the warnings about the storm.
Blithely is formed from "blithe" (from Old English "blīðe", meaning happy or cheerful) and the suffix "-ly" (meaning in a manner of). The word "blithely" means in a cheerful or carefree manner.
Think of being cheerful or happy ('blithe') and how you do something 'in that manner' ('-ly'). This helps you remember that 'blithely' means to do something in a cheerful way.