Sinlessly is an adverb that means without committing any sin or wrongdoing. Some synonyms for sinlessly include innocently, virtuously, morally, faultlessly, immaculately, and cleanly. These words describe a person's actions as pure and free from any moral stain. Sinlessly is commonly used in religious or ethical contexts, where adhering to specific rules or commandments is paramount. Adjectives such as blamelessly, guiltlessly, and irreproachably also come to mind as synonyms for sinlessly. Choosing the right word depends on the context and nuance of the sentence, but all these words ultimately convey the same sense of righteousness and purity.