Other forms: parabolically
Something that's parabolic symbolizes something or teaches a simple lesson. Many fables and Bible stories are parabolic.
If your grandfather's stories always end with him saying, "And the moral of this story is..." then you can describe them as parabolic. They are parables, in other words, tales that try to teach a moral or religious lesson. Another way to use the adjective parabolic is to mean "like a parabola," or a mathematical curve on a graph. The Greek root of parabolic is parabolikos, "figurative," from parabole, "comparison or parable," or literally "a throwing beside."