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n. pl. pi·le·i (-lē-ī′)
1. Botany The umbrellalike fruiting structure forming the top of a stalked fleshy fungus, such as a mushroom; the cap.
2. A brimless round skullcap worn by ancient Romans.
3. See caul.

[New Latin pīleus, from Latin, cap.]
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.


(ˈpaɪlɪəs; ˈpɪl-)
n, pl -lei (-lɪˌaɪ)
(Botany) the upper cap-shaped part of a mushroom or similar spore-producing body
[C18 (botanical use): New Latin, from Latin: felt cap]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˈpaɪ li əs, ˈpɪl i-)

n., pl. pi•le•i (ˈpaɪ liˌaɪ, ˈpɪl iˌaɪ)
1. the horizontal portion of a mushroom, bearing gills, tubes, etc., on its underside; a cap.
2. the umbrella or bell of a jellyfish.
3. pileum.
4. a felt skullcap worn by the ancient Romans and Greeks.
[1750–60; < New Latin; Latin pīleus felt cap; akin to Greek pîlos felt, felt cap]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.pileus - a fruiting structure resembling an umbrella or a cone that forms the top of a stalked fleshy fungus such as a mushroompileus - a fruiting structure resembling an umbrella or a cone that forms the top of a stalked fleshy fungus such as a mushroom
fungus - an organism of the kingdom Fungi lacking chlorophyll and feeding on organic matter; ranging from unicellular or multicellular organisms to spore-bearing syncytia
plant part, plant structure - any part of a plant or fungus
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
References in periodicals archive ?
Morphologically, the taxon is characterized by the presence of a medium to considerably larger pileus with glutinous to viscid surface colored gray-orange to orange white or with paler to white margin; adnate to shallowly adnexed, white, distant lamellae with 2-3 series of lamellulae; globose to subglobose basidiospores measuring 19-25x18-23 [micro]m in diameter; an ixotrichoderm type of pileipellis; well-developed, stalked, pleuro- and cheilocystidia; presence of one- to few-celled caulocystidia with heterogeneous contents; and lignicolous habit.
The polyphenol oxidase (PPO) present in the pileus (cap) and stipe (stalk) of mushrooms plays also an important role.
Pileus 67-81 mm diam., at first plane to slightly umbonated at the disc, infundibuliform in mature specimens, then slightly depressed at disc, surface smooth to slightly pruinose, margin involute, nonstriate, rimose, yellowish brown (5D5) to greyish brown (6F3) at the center, dark brown (6F5) toward the margin.
In contrast, jellyfish fauna from one of the most important fishing grounds of Argentina (San Jorge Gulf and adjacent waters in northern Patagonia), where the fisheries of the Argentine hake (Merluccius hubbsi) and the Patagonian shrimp (Pleoticus muelleri) are caught (Bezzi et al., 2004; Moriondo-Danovaro et al., 2016), seemed to be dominated by non-scyphozoan gelatinous species including the ctenophores Mnemiopsis leidyi and Pleurobrachia pileus and the hydromedusae Aequorea sp.
"Pileus" clouds are formed in a similar fashion, but in this case the wind actually blows over the top of another cloud.
Pileus 3-9cm wide, convex to hemispherical to flattened; margins straight and flaring to slightly deflexed, sometimes irregular; pileal veil white, cottony, collapsing with age and finally evanescent; pileus surface moist to viscid, yellowish white to pale yellow to yellowish brown, scales brown colored appressed fibrillose throughout the surface, more prominent towards the margin.
1-2) obtained from local markets in Nigeria, were scraped and thoroughly cleaned with water to remove sand (both the pileus and stipes), cut into smaller pieces, oven dried at 60[degrees]C, then ground and sieved to give 40 mm mesh size powder.
Pileus 30-55 mm diam., plano-convex, broadly umbonate, undulating surface, deep cinnamon to red-brown to dark brick, central disc darker, in mature specimens surface zonate, surface smooth, viscid, shiny, cap margin clearly white to cream with dentate processes, involute.
The results on the number of pileus per flushing was, in the first flush no significant difference, second flush no significant difference, third flush and the fifth flush no significant difference from each treatment.
Previous studies of Pleurobrachia pileus by Moss and Tamm (1993) demonstrated an afferent integrative center within the tentacular bulb.