Retiringly is an adverb that means in a shy, introverted, or unassertive manner. Synonyms for retiringly include bashfully, meekly, timidly, diffidently, modestly, reservedly, hesitantly, unobtrusively, shyly, and coyly. These words describe a person who is hesitant to speak up, avoids attention, and may appear withdrawn. However, it is important to note that these words do not necessarily carry a negative connotation, as shyness or reserve can be seen as a positive trait in certain situations. Overall, using a synonym for retiringly can add more nuance and depth to one's writing, especially when describing a character or their behavior.