The structure of a system or IT service, including the relationships of components to each other and to the environment they are in. Architecture also includes the standards and guidelines, which guide the design and evolution of the system.’

 Source: ITIL

Merriam-Webster Online Dictionary
architecture (noun)
the art or science of building , specifically the art or practice of designing and building structures and especially habitable ones
a) formation or construction resulting from or as if from a conscious act - the architecture of the garden
b) a unifying or coherent form or structure - the novel lacks architecture
product or work - architectural
a method or style of building
the manner in which the components of a computer or computer system are organized and integrated
Merriam-Webster Online Thesaurus
architecture (noun)
the arrangement of parts that gives something its basic form
architecture, armature, cadre, configuration, edifice, fabric, framework, framing, infrastructure, shell, skeleton, structure
cage, lattice, network; contour, figure, outline, profile, shape, silhouette; chassis
Architecture is the art and science of designing and constructing buildings and other physical structures. It involves the design of both the exterior and interior of a structure, as well as the use of materials, engineering principles, and other elements.