Illustration of foraminifer
- foraminifer shells
foraminifer
noun
for·a·min·i·fer ˌfȯr-ə-ˈmi-nə-fər 
ˌfär-
: any of an order (Foraminifera) of large chiefly marine rhizopod protozoans usually having calcareous shells that often are perforated with minute holes for protrusion of slender pseudopodia and form the bulk of chalk and nummulitic limestone
foraminiferal
fə-ˌra-mə-ˈni-f(ə-)rəl
adjective ˌfȯr-ə-mə-ˈni-
ˌfär-
Word History
First Known Use
circa 1842, in the meaning defined above