1. Slender fern of northern North America with shining chestnut-coloured stipes and bipinnate fronds with usually distinct marginal sori
   - Alpine woodsia, flower-cup fern, Woodsia alpina

Type of: woodsia

• Fourdrinier
• fourfold
• fourfold point correlation
• fourhanded
• Fourier
• Fourier analysis
• Fourier series
• fourpence
• fourpenny
• fourpenny nail
• fourscore
• foursome
• foursquare
• fourteen
• fourteenth
• Fourteenth Amendment
• fourth
• Fourth Council of Constantinople
• fourth cranial nerve
• Fourth Crusade
• fourth deck
• fourth dimension
• Fourth Earl of Chesterfield
• Fourth Earl of Orford
• fourth estate