!!

‼ (a double exclamation mark) may refer to:


 * A brilliant move in chess notation
 * The double factorial operator in mathematics
 * A "convert to Boolean" pseudo-operator in some computer languages
 * This is through a computer type of double negative, where its Boolean value is negated, then negated again, converting to the value to either true or false
 * An operator for getting the n-th element of a list in the programming language Haskell
 * A retroflex click, a family of click consonants found only in Juu languages of southern Africa and in the Damin ritual jargon of Australia

The double exclamation mark is present in Unicode as the single character U+203C DOUBLE EXCLAMATION MARK (‼) and Code page 437 at 19.