Resembling a feather in having parts or branches arranged on each side of a common axis: pinnate leaves; pinnate gills.
[Latin pinnātus, feathered, from pinna, feather; see pet- in the Appendix of Indo-European roots.]
(click for a larger image)pinnate
top: pinnate leaf
bottom: bipinnate leaf
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.