Definition of Planorbis in US English:

Planorbis

noun

Zoology
  • A genus of freshwater snails (pond snails) characterized by a rounded shell in the form of a plane spiral.

Origin

Mid 18th century; earliest use found in John Berkenhout (?1730–1791), physician and writer. From scientific Latin Planorbis, genus name (E. L. Geoffroy Traité sommaire des coquilles 12, after use as a specific name (in the genus Helix) by Linnaeus) from post-classical Latin Planorbis (J. Petiver Gazophylacii 3; also as Plan-Orbis) from classical Latin plānus + orbis.

Pronunciation

Planorbis

/pləˈnɔːbɪs/