- to change the appearance of so as to conceal identity or mislead, as with deceptive garb. 2. to conceal the truth or actual character of by a counterfeit form or appearance; misrepresent: to disguise one's intentions. n. 4. the makeup, mask, or costume of an entertainer. 5. the act of disguising. 6. the state of being disguised; masquerade.
A disguise can be anything incognito which conceals one's identity or changes a person's physical appearance, including a wig, glasses, makeup, fake moustache, costume or other items.