||Hyp`o*der"ma (?), n. [NL. See Hypo, and derma.] 1. (Bot.) A layer of tissue beneath the epidermis in plants, and performing the physiological function of strengthening the epidermal tissue. In phanerogamous plants it is developed as collenchyma.

2. (Zoöl.) An inner cellular layer which lies beneath the chitinous cuticle of arthropods, annelids, and some other invertebrates.