her·pes 
(hûrpēz)
(hûrpēz)n.
Any of several viral infections marked by the eruption of small vesicles on the skin or mucous membranes, especially herpes simplex.
[Middle English, from Latin herpēs, from Greek, from herpein, to creep.]
her·petic (hər-pĕtĭk) adj.