təˈrēd.ə̇s noun
Usage: capitalized
Etymology: New Latin, irregular from pteris fern
: a genus of ferns (family Polypodiaceae) that are sometimes included in Onoclea but distinguished by the vaselike clumps of fronds with feathery pinnate fertile fronds surrounded by or clustered among much taller sterile lanceolate fronds — see ostrich fern