n. In botany, the layer of colorless cells just beneath the epidermis of a leaf; also extended to the external cortex under the epidermis of a stem: introduced in the first sense by Kraus (1865). It is most commonly collenchyma. Also hypoderm.n. [capitalized] A genus of hypodermic dipterous insects, or botflies, of the family Œstridæ, species of which live under the skin of various ruminant and other hoofed quadrupeds. H. bovis is the bot-fly of the ox. A related species, H. linearis, is known in Texas as the heel-fly, from attacking the heels of cattle.n. [capitalized] A genus of chiropterous mammals, or bats.n. A genus of ascomycetous fungi, type of the family Hypodermataceæ, having the ascocarps elongate and opening by a longitudinal slit.