Obvod

Obvod is a Czech and Slovak noun with several related meanings across different domains.

In geometry, obvod denotes the perimeter or boundary length of a plane figure, most often the circumference of a circle. For a circle, obvod = 2πr (or πd). For polygons, it is the sum of the lengths of all sides. The term is used in everyday math as well as in technical contexts such as engineering drawings and surveys.

In administrative geography, obvod refers to a city or municipal district within a larger city or municipality. It designates a subdivision with defined borders and, in some countries, its own local authority. The term appears as městský obvod in Czech and mestský obvod in Slovak, describing districts that form part of a larger urban entity.

In electronics and daily language, obvod also means an electrical circuit—a closed path through which current can flow, including components such as resistors, capacitors, and power sources (elektrický obvod in Czech; elektrický obvod in Slovak). The word can also be used in a broader sense to denote any closed loop in practical contexts.

Other common uses include measurements of boundary length around objects, such as obvod hlavy (head circumference) or obvod pasu (waist circumference). Etymologically, the word derives from a Slavic root related to surrounding or encircling, reflecting its core sense of boundary or border.