cocoon

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A protective case of silk or similar fibrous material spun by the larvae of moths and other insects that serves as a covering for their pupal stage.
2. n. A similar natural protective covering or structure, such as the egg case of a spider.
3. n. A protective plastic coating that is placed over stored military or naval equipment.
4. n. Something suggestive of a cocoon in appearance or purpose: "a congressionally mandated process that will gradually strip these institutions of a cocoon of regulations” ( Edward Meadows).
5. v. To envelop in or as if in a cocoon, as for protection from a harsh or unfriendly environment.
6. v. To retreat as if into a cocoon, as for security from a harsh or unfriendly environment.

Century Dictionary and Cyclopedia

1. n. The silky tissue or envelop which the larvæ of many insects spin as a covering for themselves while they are in the chrysalis state. The cocoon of the silkworm is a familiar example. See cut under Bombyx.
2. n. The silken case in which many spiders inclose their eggs. In some species the mother incloses herself with the eggs until they are hatched; in others she carries the cocoon about with her, or conceals it near her web, until the young emerge.
3. n. Generally, an egg-case, such as is produced by various animals.
4. n. The South African bastard wildebeest or brindled gnu, Catoblepas gorgon. Dallas.
5. To form a cocoon.
6. To wrap as in a cocoon.

Wiktionary

1. n. The silky protective case spun by the larvae of some insects and moths in which they metamorphose, the pupa.
2. n. Any similar protective case, whether real or metaphorical.
3. v. To envelop in a protective case, or to withdraw into such a case.

GNU Webster's 1913

1. n. An oblong case in which the silkworm lies in its chrysalis state. It is formed of threads of silk spun by the worm just before leaving the larval state. From these the silk of commerce is prepared.
2. n. The case constructed by any insect to contain its larva or pupa.
3. n. The case of silk made by spiders to protect their eggs.
4. n. The egg cases of mucus, etc., made by leeches and other worms.

WordNet 3.0

1. n. silky envelope spun by the larvae of many insects to protect pupas and by spiders to protect eggs
2. v. retreat as if into a cocoon, as from an unfriendly environment
3. v. wrap in or as if in a cocoon, as for protection