pileus

[pahy-lee-uhs, pil-ee-]

noun

plural

pilei, pileus 

1. Mycology.,  the horizontal portion of a mushroom, bearing gills, tubes, etc., on its underside; a cap.

2. Zoology.

   1. the umbrella or bell of a jellyfish.

   2. pileum.

3. Also called cap cloud. Also called scarf cloud. Meteorology.,  a small, thin cloud just above or attached to a growing cumulus cloud.

4. a felt skullcap worn by the ancient Romans and Greeks.

pileus

/ ˈpɪl-, ˈpaɪlɪəs /

noun

1. the upper cap-shaped part of a mushroom or similar spore-producing body

pileus

plural

pilei 

1. The umbrellalike fruiting structure forming the top of a fleshy fungus. It is supported by the stipe. The cap of a mushroom is a pileus.

Word History and Origins

Origin of pileus¹

1750–60; < New Latin, special use of Latin pīleus skullcap; akin to Greek pîlos felt, felt cap

Word History and Origins

Origin of pileus¹

C18 (botanical use): New Latin, from Latin: felt cap