The definition of a diaspora is the dispersion of people from their homeland or a community formed by people who have exited or been removed from their homeland.(noun)
See Diaspora in Webster's New World College Dictionary
Origin: Gr diaspora, a scattering < diasperein, to scatter < dia-, across + speirein, to sow: see spore
See Diaspora in American Heritage Dictionary 4
Origin: Greek diasporā, dispersion
Origin: , from diaspeirein, to spread about
Origin: : dia-, apart; see dia-
Origin: + speirein, to sow, scatter; see sper- in Indo-European roots.