spec·i·fi·ca·tion 
(spĕs′ə-fĭ-kāshən)
(spĕs′ə-fĭ-kāshən)n.
1. The act of specifying.
2.
a. specifications A detailed, exact statement of particulars, especially a statement prescribing materials, dimensions, and quality of work for something to be built, installed, or manufactured.
b. A single item or article that has been specified.
3. An exact written description of an invention by an applicant for a patent.