• (n.) The semisolid external layer of protoplasm in some unicellular organisms, as the amoeba; ectoplasm; exoplasm.
Ec'to·sarc noun [ Ecto- + Greek ..., ..., flesh.] (Biol.) The semisolid external layer of protoplasm in some unicellular organisms, as the amœba; ectoplasm; exoplasm. 
Type: Term Pronunciation: ek′tō-sark Definitions: 1. The outer membrane, or ectoplasm, of a protozoon.