An apparition; a specter.
- Physics The distribution of a characteristic of a physical system or phenomenon, especially:
- Physics The distribution of energy emitted by a radiant source, as by an incandescent body, arranged in order of wavelengths.
- Physics The distribution of atomic or subatomic particles in a system, as in a magnetically resolved molecular beam, arranged in order of masses.
- A graphic or photographic representation of such a distribution.
- A range of values of a quantity or set of related quantities.
- A broad sequence or range of related qualities, ideas, or activities: the whole spectrum of 20th-century thought.