radical sign

noun

Mathematics.

1. the symbol √ or indicating extraction of a root of the quantity that follows it, as √25=5 or .

radical sign

noun

1. the symbol √ placed before a number or quantity to indicate the extraction of a root, esp a square root. The value of a higher root is indicated by a raised digit in front of the symbol, as in ³√

Word History and Origins

Origin of radical sign¹

First recorded in 1660–70