continuum

Short definition from Wiktionary

Noun

1. 1
   A continuous series or whole, no part of which is noticeably different from its adjacent parts, although the ends or extremes of it are very different from each other.
2. 2
   A continuous extent.
3. 3
   The nondenumerable set of real numbers; more generally, any compact connected metric space.
4. 4
   A touch-sensitive strip, similar to an electronic standard musical keyboard, except that the note steps are ¹⁄₁₀₀ of a semitone, and so are not separately marked.