Definition of rotalid in US English:

rotalid

noun

Zoology
  • A foraminiferan of the order Rotaliida, suborder Rotaliina, or superfamily Rotaliacea, having a perforate calcareous test, typically in the form of a globular spiral.

adjective

Zoology
  • Of, relating to, or characteristic of this group of foraminiferans.

Origin

Mid 19th century; earliest use found in Annals and Magazine of Natural History. From scientific Latin Rotalia + -id, after German Rotaliden, plural noun.