# Terminology question in linear algebra - a set that is closed under multiplication.

Let $$X$$ be a (real) vector space.
Let $$S$$ be a nonempty subset of $$X$$.
If $$S$$ is closed under addition and scalar multiplication,
then we call $$S$$ a subspace.
If $$S$$ is closed under multiplication by nonnegative scalars,
then we call $$S$$ a cone (that may or may not be convex).

My question is:

What do we call $$S$$ if $$S$$ is closed under scalar multiplication?

Note: $$S$$ need not be closed under addition.