Noun | 1. | ![]() U.S.A., United States, United States of America, US, USA, America, the States, U.S. - North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776 fern - any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores Acrostichum, genus Acrostichum - in some classification systems placed in family Polypodiaceae |
2. | leather fern - widely distributed fern of tropical southern hemisphere having leathery pinnatifid fronds fern - any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores genus Rumohra, Rumohra - leatherleaf ferns: in some classifications included in genus Polystichum |