A relational symbol denoting that one set contains another as a subset in set theory.
Examples
Basic set containment
\{1, 2, 3\} \supset \{1, 2\}
Number set inclusions (reverse order)
\mathbb{R} \supset \mathbb{Q} \supset \mathbb{Z} \supset \mathbb{N}
Set theory with variables
A \supset B \text{ means B is a proper subset of A}