pileus

The umbrellalike fruiting structure forming the top of a stalked fleshy fungus, such as a mushroom; the cap.

A brimless round skullcap worn by ancient Romans.

A nipple-shield.

The disk or umbrella of a jellyfish.

Among the ancient Romans, a conical cap or hat of felt; a cap or skullcap.

In botany, the expanded cap-like or umbrella-like summit of the stipe, bearing the hymenium, in hymenomycetous fungi: same as cap, 2 . See cuts under Agaricus and Fungi.

In ornithology, same as pileum.

[capitalized] [NL.] A genus of echinoderms.

A kind of skull cap of felt.