mesophyll
noun
me·so·phyll ˈme-zə-ˌfil 
ˈmē-
ˈmē- -sə-
: the parenchyma between the epidermal layers of a foliage leaf
mesophyllic
ˌme-zə-ˈfi-lik
adjective ˌmē-
-sə-
or mesophyllous
ˌme-zə-ˈfi-ləs
ˌmē-,
-sə-
Word History
Etymology
New Latin mesophyllum, from mes- + Greek phyllon leaf — more at blade
First Known Use
1848, in the meaning defined above