allegory (n.)

"figurative treatment of an unmentioned subject under the guise of another similar to it in some way," late 14c., from Old French allegorie (12c.), from Latin allegoria, from Greek allegoria "figurative language, description of one thing under the image of another," literally "a speaking about something else," from allos "another, different" (from PIE root *al- (1) "beyond") + agoreuein "speak openly, speak in the assembly," from agora "assembly" (see agora). Related: Allegorist.