The word "stonily" describes something that is done in a cold, unemotional way. There are several synonyms that can be used in place of this word depending on context. "Dully" can be used to describe a lack of expression or emotion in a person's face, while "rigidly" can convey a stiffness or inflexibility in a person's behavior. "Coldly" can be used to describe a lack of warmth or empathy, while "remotely" suggests a detachment or distance in a person's demeanor. Finally, "unresponsively" can be used to describe a lack of reaction or response to something. Each of these words helps to convey the sense of detachment or lack of emotion associated with stonily.