IGY explained

IGY may refer to:

Immunoglobulin Y (IgY), a type of antibody found in birds but not mammals
International Geophysical Year (I. G. Y.)
"I.G.Y. (What a Beautiful World)", a 1982 song by Donald Fagen
Israel Gay Youth
Ingenuity (helicopter) (ICAO operator code: IGY), NASA defunct solar-powered autonomous drone helicopter on Mars

See also