"In disguise" is a phrase used to describe someone or something that is hidden or appears differently than its true form. There are various synonyms that can be used to convey this meaning, including undercover, incognito, disguised, camouflaged, masked, and concealed. "Undercover" refers to someone who is working secretly to gather information without revealing their true identity. "Incognito" is used to describe someone who is trying to avoid being recognized or identified. "Disguised" and "camouflaged" highlight the aspect of something being hidden or appearing differently. "Masked" and "concealed" also suggest that something is hidden or not readily apparent. All of these synonyms convey the idea of something or someone being disguised or hidden in some way.