cocoon  
 noun uk/kəˈkuːn/ us/kəˈkuːn/
  (COVER)     
  [ C ]茧;卵袋 
the covering made of soft, smooth threads that surrounds and protects particular insects during the pupa stage as they develop into adult form
   (PROTECTED PLACE)      
 [ C usually singular ]安全宁静的地方;避风港 
a safe, quiet place
  the warm, safe cocoon of childhood 童年生活的温馨安逸、备受呵护 
 cocoon       
verb [ T usually passive ] uk/kəˈkuːn/ us/kəˈkuːn/
 给…加上保护层,将…裹住
to protect someone or something from pain or an unpleasant situation
  As a student you're cocooned against/from the real world. 作为一名学生,你处在与现实世界隔离的环境之中。