Silky covering spun around some insect larvae

noun

1. An envelope often largely of silk which an insect larva forms about itself and in which it passes the pupa stage
2. Any of various other protective coverings produced by animals
3. Something suggesting a cocoon especially in providing protection or in producing isolation

   "wrapped in a cocoon of blankets"

4. A protective covering placed or sprayed over military or naval equipment in storage

verb

1. To wrap or envelop in or as if in a cocoon