noun 1.a cardinal number, 70 plus 5.
2.a symbol for this number, as 75 or LXXV.
3.a
set of this many persons or things.
4.Military.a.a gun with a 75-mm caliber.
b.the field gun of that caliber used in the French and U.S. armies in World War I.
adjective 5.amounting to 75 in number.