pinnigrade definition by American Heritage Dictionary
The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Walking by means of finlike organs or flippers, as the seals and walruses.
Origin: pinn(a) + Latin -gradus, going (from gradī, to step; see ghredh- in Indo-European roots).
pinnigrade - Science Definition
Walking by means of finlike organs or flippers, as seals and walruses.