ep·i·der·mis 
(ĕp′ĭ-dûrmĭs)
(ĕp′ĭ-dûrmĭs)n.
1. The outer, protective, nonvascular layer of the skin of vertebrates, covering the dermis.
2. An integument or outer layer of various invertebrates.
3. The outermost layer of cells covering the leaves and young parts of a plant.
[Late Latin, from Greek : epi-, epi- + derma, skin; see der- in the Appendix of Indo-European roots.]
ep′i·dermal (-məl), ep′i·dermic adj.