Source : Webster's Revised Unabridged Dictionary (1913)

Mesogloea \Mes`o*gl[oe]"a\, n. [NL., fr. Gr. me`sos middle + ? a
   glutinous substance.] (Zo["o]l.)
   A thin gelatinous tissue separating the ectoderm and endoderm
   in certain c[oe]lenterates. -- {Mes`o*gl[oe]"al}, a.