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.n. A similar natural protective covering or structure, such as the egg case of a spider.n. A protective plastic coating that is placed over stored military or naval equipment.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). v. To envelop in or as if in a cocoon, as for protection from a harsh or unfriendly environment.verb-intransitive. To retreat as if into a cocoon, as for security from a harsh or unfriendly environment.