1. Variant of -aceous.
2. An organism belonging to a taxonomic group: cetacean.
[From New Latin -ācea, neuter pl. of -āceus, -aceous.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.