decas

Decas is a term that lacks a single, universally accepted definition. Its meaning varies by language and discipline, and in many cases it appears only as a plural form of a root rather than as a standalone concept. The most common origin is the Greek deka, meaning ten, which gives rise to the scientific prefix deca- (or deka-) used to denote multiples of ten in units such as decameters or decagrams. In ordinary English prose, decas is not a standard unit or term, and its appearance usually reflects either a linguistic variant, a transcription choice, or a specialized shorthand in a particular field.

In some contexts decas may be encountered as a plural noun indicating ten-item groups, or as a proper noun in names of places, organizations, or fictional works. Because usage is inconsistent, readers should pay close attention to surrounding text for the intended meaning.

See also: deca-, decade, decagon, decalitre, decagram.