"By stealth" is a phrase often used to describe actions or behaviors taken in a secretive or sly manner. There are several synonyms for this phrase, including covertly, surreptitiously, furtively, secretly, clandestinely, and stealthily. Each of these words captures the idea of doing something in a way that is concealed from others, whether it is for strategic purposes or to avoid detection or scrutiny. By using synonyms for "by stealth," writers and speakers can add nuance and variety to their language, making their messages more engaging and impactful.