The best example of a domain-specific language (DSL) among the provided options is "shape." Domain-specific languages are tailored to specific application domains, such as graphics, data manipulation, or configuration settings. "Shape" could refer to a DSL used in graphics programming or design that focuses specifically on defining and manipulating geometric shapes.
The other terms "close," "numerous," and "equilateral" are more general terms and do not distinctly represent a domain-specific language.