It's already a complete word, meaning cheerful and carefree.
Here's why there might not be a suffix:
* Meaning: The meaning of "blithe" is already very specific and doesn't easily lend itself to extensions with suffixes.
* Structure: The word is short and simple, making it difficult to add a suffix without changing its pronunciation or meaning significantly.
If you're looking for a similar word with a suffix, you might consider:
* Blithesome: This means cheerful or happy.
* Blithefully: This is an adverb meaning in a cheerful or carefree way.