Zoology. an underlayer of epithelial cells in arthropods and certain other invertebrates that secretes substances for the overlying cuticle or exoskeleton.
2.
Botany. a tissue or layer of cells beneath the epidermis.
Main Entry: hy·po·der·mis Pronunciation: "hI-p&-'d&r-m&s Function: noun 1: the cellular layer that underlies andsecretes the chitinous cuticle (as of an arthropod) 2:SUPERFICIAL FASCIA