1. Yellow-green fern of rocky areas of northern hemisphere
   - northern oak fern, Gymnocarpium robertianum

Derived forms: limestone ferns

Type of: fern

• thuggee
• thuggery
• thuggish
• Thuja
• Thuja occidentalis
• Thuja orientalis
• Thuja plicata
• Thujopsis
• Thujopsis dolobrata
• Thule
• thulium
• thumb
• thumb index
• thumbed
• thumbhole
• thumbnail
• thumbnut
• thumbprint
• thumbs-down
• thumbs-up
• thumbscrew
• thumbstall
• thumbtack
• thump
• thump out