Allegory - (Webster's 1828 Dictionary)
AL'LEGORY, n. [Gr. other, to speak, a forum, an oration.]
A figurative sentence or discourse, in which the principal subject is described by another subject resembling it in its properties and circumstances. The principal subject is thus kept out of view, and we are left to collect the intentions of the writer or speaker, by the resemblance of the secondary to the primary subject. Allegory is in words that hieroglyphics are in painting. We have a fine example of an allegory in the eightieth Psalm, in which God's chosen people are represented by a vineyard. The distinction in scripture between a parable and an allegory, is said to be that a parable is a supposed history, and an allegory, a figurative description of real facts. An allegory is called a continued metaphor. The following line in Virgil is an example of an allegory.
Claudite jam rivos, pueri, sat prata biberunt.
Stop the currents, young men, the meadows have drank sufficiently; that is let your music cease, our ears have been sufficiently delighted.