noun

• A type of sauce made from milk and eggs (and usually sugar, and sometimes vanilla or other flavourings) and thickened by heat, served hot poured over desserts, as a filling for some pies and cakes, or cold and solidified; also used as a base for some savoury dishes, such as quiches, or eaten as a stand-alone dessert; egg custard.
• (by extension) A similar sauce made from milk and cornflour or custard powder (and usually sugar, and sometimes vanilla or other flavourings) and thickened by heat.
• A surname.