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Related to pinnule: pinnation
pin·nule(pĭn′yo͞ol) also pin·nu·la (pĭn′yə-lə)
n. pl. pin·nules also pin·nu·lae (pĭn′yə-lē′)
1. Botany One of the secondary divisions of a binnately compound leaf.
2. Zoology A small featherlike part or subdivision of an appendage, especially one of the small branches on the arm of a crinoid.
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.
n, pl pinnules or pinnulae (ˈpɪnjʊˌliː)
1. (Botany) any of the lobes of a leaflet of a pinnate compound leaf, which is itself pinnately divided
2. (Zoology) zoology any feather-like part, such as any of the arms of a sea lily
[C16: from Latin pinnula, diminutive of pinna feather]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
1. a part or organ resembling a barb of a feather, a fin, or the like.
2. a secondary pinna, one of the pinnately disposed divisions of a bipinnate leaf.
[1585–95; < Latin pinnula, diminutive of pinna feather; see -ule]
pin′nu•lar (-yə lər) adj.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.