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 (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.

[Latin pinnula, diminutive of pinna, feather; see pet- in Indo-European roots.]

pin′nu·lar adj.


(ˈpɪnjuːl) or


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]
ˈpinnular adj


(ˈpɪn yul)

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.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.pinnule - division of a usually pinnately divided leafpinnule - division of a usually pinnately divided leaf
leaflet - part of a compound leaf
References in periodicals archive ?
The angular diameter of sun and moon is calculated based on the width of the hole on the outer pinnula and the distance between the pinnulae.
The morphological study of the sporophyte was based on foliar architecture, indument, epidermal patterns of pinnulae and indusium, spore size (mean values between 28.