| quantum leap or quantum jump | |
| —n | |
| a sudden highly significant advance; breakthrough | |
| [C20: from its use in physics meaning the sudden jump of an electron, atom, etc from one energy level to another] | |
| quantum jump or quantum jump | |
| —n | |
| [C20: from its use in physics meaning the sudden jump of an electron, atom, etc from one energy level to another] | |
| a chattering or flighty, light-headed person. |
| a children's mummer's parade, as on the Fourth of July, with prizes for the best costumes. |
| quantum jump
A change from one quantum state to another, as when an electron orbiting a nucleus moves from one shell to another with the loss or gain of a quantum of energy. |