Also found in: Wikipedia.
Hurry up! Move faster! The phrase originated as an instruction used when trying to get a horse to move faster. Come on, kids, giddy up—the school bus will be here any minute!
exclam. Move faster! (Properly said to a horse to start it moving. Also said to people or things as a joke.) Giddy up, Charlie! It’s time to start moving.
See also: giddy