[ pin-yool ]
/ ˈpɪn yul /


  1. a part or organ resembling a barb of a feather, a fin, or the like.
  2. a finlet.
Botany. a secondary pinna, one of the pinnately disposed divisions of a bipinnate leaf.
a metal plate with a small hole in it, used as a sight in a quadrant.


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Origin of pinnule

1585–95; < Latin pinnula pinnula


pin·nu·lar [pin-yuh-ler] /ˈpɪn yə lər/, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for pinnule

British Dictionary definitions for pinnule


pinnula (ˈpɪnjʊlə)

/ (ˈpɪnjuːl) /

noun plural pinnules or pinnulae (ˈpɪnjʊˌliː)

any of the lobes of a leaflet of a pinnate compound leaf, which is itself pinnately divided
zoology any feather-like part, such as any of the arms of a sea lily

Derived forms of pinnule

pinnular, adjective

Word Origin for pinnule

C16: from Latin pinnula, diminutive of pinna feather
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for pinnule

[ pĭnyōōl ]

Any of the smaller leaflets into which each leaflet of a bipinnately compound leaf is subdivided. The leaves of many ferns are divided into pinnules.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.