(Computers) An artificial computer language with mnemonic codes representing the basic machine-language instructions of a computer, which can be interpreted by an assembler to produce a computer program in machine language. Also informally referred to as assembler. Note: Writing a program in assembly language is very much simpler than writing the machine instructions in binary code, and the use of such a language greatly increases the efficiency of the process of writing computer programs. See also programming language, FORTRAN, BASIC.