Definition of mesocyst in US English:

mesocyst

noun

  • Biology. The middle layer of the wall of certain protozoan cysts.

Origin

Late 19th century (in an earlier sense). From meso- + cyst J. S. Billings records also a French form mésocyste.

Pronunciation

mesocyst

/ˈmɛsə(ʊ)sɪst/