Let’s say you have a range of things to choose from. If you need to refer to all those choices collectively, the word you want is spectrum. Guard against using the phrase whole spectrum, which is unnecessarily redundant -- a spectrum is, by definition, something whole. To qualify as a spectrum, everything in this realm must somehow be linked, however loosely that may be. This stems from more specific uses of spectrum, which commonly pertains to the color wheel. On the color spectrum, colors are arranged in gradual order, as they appear when light passes through a prism. And note that the plural of spectrum is spectrums. Though in some technical contexts, you might encounter spectra--that’s the Latin plural. But this isn’t Latin. If it were, the word spectrum would refer to the appearance of an apparition. Consider the word specter. Today specter is usually a group of negative possibilities, though it was originally a ghost -- a use we still use. Comparing the shift in spectrum with the word scope, used in the scope of potential solution. Ghosts have a funny way of hiding, even behind seemingly innocuous words.
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