Merriam-Webster Collegiate Dictionary - symbolism

 noun  Date: 1654  1. the art or practice of using symbols especially by investing things with a symbolic meaning or by expressing the invisible or intangible by means of visible or sensuous representations: as  a. artistic imitation or invention that is a method of revealing or suggesting immaterial, ideal, or otherwise intangible truth or states  b. the use of conventional or traditional signs in the representation of divine beings and spirits  2. a system of symbols or representations