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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.]


(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]


(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]
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
References in periodicals archive ?
It was stated that the pileus and stipe of the mushroom are cut into pieces, boiled and added to okro or vegetable soup [1].
completely overgrown with ivy" (a second time), "the onion" (again), "the Pharisees [again] or Round-heads," "The whirlpool of the ocean," "The hog" (which only "appears a large animal; but when cut across, it presents a form like that of the onion"--again), "death" (again), "The pileus, or hat of Mercury," and "the skull" (681).
Nine updated papers discuss such topics as historical climate trends in Michigan and the Great Lakes region, the power of understanding judgment and decision processes, whether uncertain information is usable knowledge for agricultural adaptation to climate change, linking science to decision making in the region, and the Pileus Project as an example of the development and communications of an ensemble of local-scale climate scenarios.
Thickness of the pileus of four randomly selected fruiting bodies was recorded using a slide calliper.
Pileus 2-8 cm across, hemispherical when young, later convex with an incurved margin, eventually plane, surface smooth, slightly lubricous, dark gray when young, later gray-brown to light gray.