What's the difference between i.e. and e.g.?
1717, from Modern Latin prodromus "a running forward" (see prodrome) + -al (1).
1640s, from French prodrome (16c.), from Modern Latin prodromus, from Greek prodromos "a running forward, a sally, sudden attack," from pro- "forward" (see pro-) + dromos "a running" (see dromedary).
prodrome pro·drome (prō'drōm')n. pl. pro·dromes or pro·dro·ma·ta (-drō'mə-tə) An early symptom indicating the onset of an attack or a disease.