pan·dem·ic 
(păn-dĕmĭk)
(păn-dĕmĭk)adj.
1. Widespread; general.
2. Medicine Epidemic over a wide geographic area and affecting a large proportion of the population: pandemic influenza.
n.
A pandemic disease.
[From Late Latin pandēmus, from Greek pandēmos, of all the people : pan-, pan- + dēmos, people; see dā- in the Appendix of Indo-European roots.]