red-berry red·berry uncommon noun 1. small spiny evergreen shrub of western United States and Mexico with minute flowers and bright red berries SynonymsredberryRhamnus croceus 2. North American perennial herb with alternately compound leaves and racemes of small white flowers followed by bright red oval poisonous berries Synonymsred baneberryredberrysnakeberryActaea rubra Related words Broader terms baneberrybuckthorn WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.