Wiktionary
n. (context topology English) A regular space with the additional property that for every disjoint pair of closed sets in that space, there is a disjoint pair of open sets which contain the closed sets, respectively.
Wikipedia
In topology and related branches of mathematics, a normal space is a topological space X that satisfies Axiom T: every two disjoint closed sets of X have disjoint open neighborhoods. A normal Hausdorff space is also called a T space. These conditions are examples of separation axioms and their further strengthenings define completely normal Hausdorff spaces, or T spaces, and perfectly normal Hausdorff spaces, or T spaces.
Usage examples of "normal space".
As soon as the convoy emerged into normal space it would be boxed in, would be obliterated by overwhelming fire.
We didn't tell you because we only had the one lift to Mars to go by and there was enough time between our lift and their getting those critical replacement units that it could have been a normal space translation.
If the craft comes near enough it will precipitate into normal space.
The apparatus was reduced to a size that a normal space ship could contain, by use of some of Anlo's wonderful insulating materials.
The Queen made transition into normal space on schedule within Limbo’.
Nobody could guess within a million miles where she'd break out into normal space.
Whatever the puppeteers were using probably couldn't find us in normal space.