含羞 is an adverb meaning 'shyly' or 'timidly', describing how someone does something with a bashful or embarrassed demeanor. It often pairs with 地 (de) before the verb it modifies. The word literally combines 含 ('to hold in the mouth') and 羞 ('shame/shyness'), evoking the image of someone holding back their shyness. It's a literary or formal register word, more common in written Chinese than everyday speech.