The Great Plains, the Midwest, the Mississippi Valley and the southern United States are all areas that are vulnerable to tornadoes. They are relatively rare west of the Rockies and are also less frequent in the northeastern states. Tornado Alley is a colloquial term for an area particularly prone to tornadoes.
GCIDE(0.00 / 0 votes)Rate this definition: 1  Limpid(a.) Clear and unambiguous; lucid; easy to understand; -- of speech and writing; as, limpid prose. 2  Limpid(a.) Calm, untroubled, and without worry; serene.
Top definition. factoid. a not-entirely-true or documentable fact that can be used alone or used to embellish a story; see Anneism. During the Anneism spouted by Gertrude, the factoids were flying fast and furious.