foraminifer
Concise Oxford English Dictionary © 2008 Oxford University Press:
foraminifer /ˌfɒrəˈmɪnɪfə/
▶noun (pl. foraminifers or foraminifera /ˌfɒrəmɪˈnɪf(ə)rə/) Zoology a single-celled planktonic animal with a perforated chalky shell through which slender protrusions of protoplasm extend. [Order Foraminiferida.]
– derivatives
foraminiferal /ˌfɒrəmɪˈnɪf(ə)rəl/ adjective,
foraminiferan noun & adjective,
foraminiferous adjective.
foraminiferal /ˌfɒrəmɪˈnɪf(ə)rəl/ adjective,
foraminiferan noun & adjective,
foraminiferous adjective.
'foraminifer' also found in these Oxford entries:

