# Word for the object that encircles another object

What is a single word for something that is used to encircle another object? For example, a general name for rings that encircle Saturn. 'Encirclage' is my guess, but it seems the word doesn't exist.

Sample sentence:

The encircled regions are complete events. The geometrical shape of the ______ could be any closed polygon.

• It might depend on usage - e.g. fence, perimeter and satellite might work in different contexts. Is your specific context the rings of Saturn? Feb 14, 2018 at 14:11
• Perhaps belt. Feb 14, 2018 at 14:13
• @Lawrence No. I have regions on a 2d plane enclosed by different contours. They are not literally 'circles'. Feb 14, 2018 at 14:14
• It depends on the number and sort of dimensions involved relative to the domain. Encircling suggests a line or disc that lies in a subspace of the domain; as opposed to something like a bag that lies in the entire domain, but which might be able to be described parametrically in fewer dimensions. A spherical shell is a 2D surface in a 3D domain defined by one parameter. Saturn's rings are, to a first approximation, a set of coplanar annuli, so they are 2D surface in a 2D subspace defined by 2 parameters. So you need to explain what you mean (and don't mean) by encircle in these terms. Feb 14, 2018 at 15:20

Consider encirclement:

encirclement noun See encircle ‘The latest outrage was the encirclement of the city, cutting it off and isolating it from its environment through barricades.’ - ODO

That definition isn't particularly illuminating, so here's the ODO entry it references for encircle:

Form a circle around; surround.

Your example would look like this:

• The encircled regions are complete events. The geometrical shape of the encirclement could be any closed polygon.
• I think that my idea of ‘surround’ fits better as it does not have to be circular. And I find it a bit difficult to understand the sentence given in the question, when using the word ‘encirclement’. I think if you try substituting ‘surround’ it is clearer. Feb 15, 2018 at 1:47

In English there's no single word for the different types of topological surroundation.

There are also difficulties with 2D versus 3D situations.

• Saturn-like situation: The XYZ encircles the planet, or just, the XYZ circles the planet.

(Note that one meaning of "circles" is identical to "encircles".)

• A farm, with something like a "clos" (as in French) around it. The XYZ encloses the farm.

• A handheld object such as, say, loaf of bread. The xyz wraps around it.

• A more "general" surroundation. The xyz encompasses the baseball field. THe XYZ encompasses the city center.

"Circle" (or "encircle") is probably closest to being able to be used in all cases; but it leans towards the 3D.

Realize that with many SWR, the correct answer is, there is no such SWR in English.

If you're literally asking about Saturn or similar topological/metric domains you're probably looking for "encircles".

Regarding more 3D issues, there is no really good word for it. (You could make up "enspherization" for technical use, based on encirclization, if you work in 3D graphics engineering. You can sometimes use "clothes" or "skins" in such a technical setting.) You normally have to use a phrase like "wraps completely around" or "covers all sides". Example, "the shrink-wrap completely covers the bowling ball all around", etc.

It fits your example sentence like this:

'The geometrical shape of the surround could be any enclosed polygon.'

It means: 'To be all around someone or something'.

And: 'A thing that forms a border or edging around an object'.

It does not have to be circular. It can be any shape. It can be 2D or 3D.

Examples:

• Saturn has a surround of light

• The farm is enclosed by a stone surround

• The bread has a surround of paper

• The marsh has a surround of sand-dunes

• The house has a surround of grass

• The cake has a surround of icing