The Collaborative International Dictionary
Thysanuran
Thysanuran \Thys`a*nu"ran\, n. (Zo["o]l.) One of the Thysanura. Also used adjectively.
Wiktionary
thysanuran
n. Any of various insects, including the silverfish and firebrats, of the order ''(taxlink Thysanura order noshow=1)'', which have three long caudal filaments.