wall rue wall·rue uncommon noun 1. small delicate spleenwort found on a steep slope (as a wall or cliff) of Eurasia and North America Synonymswall ruewall rue spleenwortAsplenium ruta-muraria Related words Word family wall rue spleenwort Broader terms spleenwort WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.