Any of numerous extinct marine arthropods of the class Trilobita, of the Paleozoic Era, having a segmented body divided by grooves into three vertical lobes and found as fossils throughout the world. (noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "trilobite" in a sentence
"A trilobite is a tri-lobed water bugessentially from the prehistoric age, one of the first life forms of it's kind, and a cornerstone of anyone's fossil collection."
"Millstone asked Freshwater several questions about another survey, in which students apparently were shown a prehistoric fossil called a trilobite and asked to describe it."
"The original Trilobite: The trilobite was a type of arthropod that vacuumed the ocean beds for small animals and particles about 250-560 million years ago."