Ordinary space (or just space) is a word used to mean the universe we live in.
Hence ordinary space is usually taken as an alternative term for Euclidean $3$-dimensional space.
Also known as
Ordinary space can also be referred to as physical space but that term is also used in common parlance to mean a particular volume for day-to-day deployment of stuff.
- I would love to take my entire collection of cuddly toys on holiday with me to St. Petersburg, but I don't have the physical space in my suitcase.
In a wider sense, the term natural world can be used.
- 1942: William H. McCrea: Analytical Geometry of Three Dimensions: $\S 1$
- 1952: T. Ewan Faulkner: Projective Geometry (2nd ed.) ... (previous) ... (next): $1.2$: The projective method
- 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $3$
- 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $3$