Any of several shrubs of the chiefly Mediterranean genus Iberis; especially I. saxatilis, which has white flowers and is sometimes cultivated as a rockery plant.
Origin
Early 19th century.
Definition of rock candytuft in US English:
rock candytuft
noun
Any of several shrubs of the chiefly Mediterranean genus Iberis; especially I. saxatilis, which has white flowers and is sometimes cultivated as a rockery plant.