Square root

RADICAL

Think of the mathematical symbol that often looks like a stretched checkmark before a number.

The clue "Square root" hints at the mathematical symbol for roots, which is the radical sign (√). In math terms, a "radical" refers to the root of a number, so the answer plays on that direct meaning. It’s a straightforward definition where the word itself names the symbol used in equations. No tricks—just a clean link between the term and its mathematical identity.