Secret language

Secret language may refer to:
 * Cant (language), also known as cryptolect, the jargon or argot of a group, often employed to exclude or mislead people outside the group
 * Argot, strictly a proper language with its own grammar, used to prevent understanding by outsiders; sometimes argot is used as a synonym of cant or jargon
 * Sacred language, also called a ceremonial or a ritual language, which is only learned and used by a select initiated group