pileus

Definition of Pileus in English :

1. cap, pileus

a fruiting structure resembling an umbrella or a cone that forms the top of a stalked fleshy fungus such as a mushroom

WordNet Lexical Database for English. Princeton University. 2010.

Pileus

noun plural -lei (-lɪˌaɪ)

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

nounWord forms: plural ˈpileˌi (ˈpaɪliˌaɪ ; pīˈlēīˌ; ˈpɪliˌaɪ ; pilˈēīˌ)

1.

a type of brimless cap worn in ancient Rome

2. Botany

the cap of a mushroom, or the similar part of the fruiting body of other fungi

3. Zoology

a.

the umbrella-shaped disk of a jellyfish

b.

pileum

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.