- Proper noun. (US) The lower legislative body of each of a number of states of the United States, ("the Assembly").
- Noun. A set of pieces that work together in unison as a mechanism or device.
- Noun. A congregation of people in one place for a purpose.
- Noun. A legislative body; e.g., the General Assembly of the United Nations.
- Noun. (computing) A shortened or jargon form of the term ''assembly language''.
- Noun. (computing) In Microsoft .NET, a building block of an application, similar to a DLL, but containing both executable code and information normally found in a DLL's type library. The type library information in an assembly, called a manifest, describes public functions, data, classes, and version information.