n., pl., -tra (-trə), or -trums.
- Physics. The distribution of a characteristic of a physical system or phenomenon, especially:
- The distribution of energy emitted by a radiant source, as by an incandescent body, arranged in order of wavelengths.
- 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.
[Latin, appearance, from specere, to look at.]
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
