1Botany. Resembling or shaped like a mitre; (specifically of the calyptra of a moss) conical, symmetrical, and having two or more slits.
2Zoology. Resembling a mitre shell.
Origin
Early 19th century; earliest use found in Robert Kaye Greville (1794–1866), botanist. From scientific Latin mitriformis from classical Latin mitra + -formis.