any of various plants, especially of the genera Ipomoea and Convolvulus, as I. purpurea, a twining plant having cordate leaves and funnel-shaped flowers of various colors, often opening only in the morning.
a racehorse that runs faster in morning workouts than in afternoon races.
Origin of morning glory
An Americanism dating back to 1805–15
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019