tsetse UK /ˈtsɛtsi/US /ˈtsitsi/ noun1 •Any fly of the genus Glossina, native to Africa, that feeds on human and animal blood; known primarily as a carrier of parasitic trypanosomes.Species of Trypanosoma transmitted by tsetse cause diseases of economic importance in humans and domestic animals in sub-Saharan Africa. — 1999 formstsetses