Definition of nummulitid in US English:

nummulitid

noun

Zoology
  • A foraminiferan of the family Nummulitidae, variously defined by different writers but including the nummulites.

adjective

Zoology
  • Of, relating to, or designating foraminiferans of the family Nummulitidae.

Origin

Late 19th century; earliest use found in Isaac Funk (1839–1912), publisher and reformer. From scientific Latin Nummulitidae, family name from Nummulites + -idae.