EaD or EAD may be:

• Employment authorization document, in U.S. employment
• Encoded Archival Description, a standard for encoding archival finding aids
• Equivalent air depth, in diving with nitrox
• EAD-socket (German: Ethernet-Anschlussdose), a wall socket for Ethernet connections
• European AIS Database, in European aviation
• Exposure at default (EAD), in finance (Basel II)
• Station code for Earlsfield railway station in London
• Extreme Anxiety Disorder, an intensified version of Anxiety Disorder

Id. (masculine) and Ead. (feminine) (Latin, short for "idem" and "eadem", "the same") are the terms used to denote the previously cited source (compare ibid.). Id. is particularly used in legal citations. They are also used in academic citations where the term replaces the name of a repeated author. Id. is used extensively in Canadian legislation to apply a short description to a section with the same focus as the previous.