In thermodynamics, the part of the universe not included in the system.

The rest of the universe, excepting the system.

That portion of the universe that is not the system.

or context (entour): the totality of the semiotic phenomena associated with a linguistic sequence; more generally, a non linguistic context.

Surroundings are the area around a given physical or geographical point or place. The exact definition depends on the field. Surroundings can also be used in geography and mathematics, as well as philosophy, with the literal or metaphorically extended definition.

the environmental condition

the physical structures and environmental conditions around an organism.

the area in which something exists or lives; "the country--the flat agricultural surround"