Physical Architecture (glossary)
An arrangement of physical elements which provides the design solution for a consumer product or life-cycle process intended to satisfy the requirements of the functional architecture and the requirement baseline. (ISO/IEC 2007)
ISO/IEC. 2007. Systems and Software Engineering -- Recommended Practice for Architectural Description of Software-Intensive Systems. Geneva, Switzerland: International Organization for Standards (ISO)/International Electronical Commission (IEC), ISO/IEC 42010:2007.
Discussion as to why this is the "consensus" definition for the SEBoK.