sac

 
Pronunciation: /sak/

noun

  • a hollow, flexible structure resembling a bag or pouch: a fountain pen with an ink sac
  • a cavity within an organism, enclosed by a membrane and containing air, liquid, or solid structures.
  • the distended membrane surrounding a hernia, cyst, or tumour.

Derivatives

sac-like

adjective

Origin:

mid 18th century (as a term in biology): from French sac or Latin saccus 'sack, bag'