a device for showing the operating condition of some system
a signal for attracting attention
(chemistry) a substance that changes color to indicate the presence of some ion or substance; can be used to indicate the completion of a chemical reaction or (in medicine) to test for a particular reaction
a part of a structure having some specific characteristic or function; "the spacious cooking area provided plenty of room for servants"
the extent of a 2-dimensional surface enclosed within a boundary; "the area of a rectangle"; "it was about 500 square feet in area"
a part of an animal that has a special function or is supplied by a given artery or nerve; "in the abdominal region"
a subject of study; "it was his area of specialization"; "areas of interest include..."
a particular geographical region of indefinite boundary (usually serving some special purpose or distinguished by its people or culture or geography); "it was a mountainous area"; "Bible country"