What does IGU stand for?

Iguassu Falls - Brazil - Airport symbol (OAG)

Iminoglycinuria - Medicine (MELL)

Infantile Gastroenteritis Virus - Medicine (PDAA)

Instituto Geografico Universitario - University Geographic Institute (GIS)

Interfaz Grafica de Usuario - Graphical User Interface

Internationale Gewerbeunion - International Association of Crafts and Small and Medium Sized Enterprises - IACME - Berne, Switzerland (EAIO)

International Gas Union - See also UIIG (EAIO)

International Geographical Union - ICSU - Edmonton, AB (EA)

International Geophysical Union