Greater-than or slanted equal to

It means “greater than or equal to.”

In x ⩾ 5, x may be larger than 5 or exactly 5; the sign compares the expressions on its two sides.

The slanted equality stroke is a typographic variant of ≥ and expresses the same relation.

How did the notation develop?

The history of the relation goes back earlier than this exact slanted character. In 1670, John Wallis used a form with one bar above the greater-than or less-than sign; in 1734, Pierre Bouguer used two bars below it.

Those are earlier ways to write the relation, not evidence that either mathematician used ⩾ itself. The familiar ≥ has a horizontal equality bar; ⩾ is the slanted typographic counterpart.

How do I type the slanted form?

Use \geqslant in LaTeX with unicode-math.

LaTeX is a system for typesetting documents; unicode-math is a package for mathematical Unicode fonts.

A usual greater-than-or-equal shortcut may produce ≥. In unicode-math, \geqslant selects the slanted form; \geq selects the familiar horizontal-bar form.