Ischemia
The word "ischemia" () is from Greek ἴσχαιμος "iskhaimos", "staunching blood" from ἴσχω "iskhο", "keep back, restrain" and αἷμα "haima", "blood".
Epidemic
An epidemic (from Greek ἐπί "epi" "upon or above" and δῆμος "demos" "people") is the rapid spread of infectious disease to a large number of people in a given population within a short period of time, usually two weeks or less. For example, in meningococcal infections, an attack rate in excess of 15 cases per 100,000 people for two consecutive weeks is considered an epidemic.