any New World plant of the genus Agave, requiring many years to mature and blooming once before dying, especially the widely cultivated species A. americana, having leaves in a basal rosette and a tall flower stalk.
The leaves of the century plant have a blue-gray color.
British Dictionary definitions for century plant
an agave, Agave americana, native to tropical America but naturalized elsewhere, having very large spiny greyish leaves and greenish flowers on a tall fleshy stalk. It blooms only once in its life, after 10 to 30 years (formerly thought to flower after a century) Also called American aloe