Lacking any natural basis or substantial justification. In the theory of the sign elaborated by the Swiss linguist Ferdinand de Saussure, the relationship between the signifier (the sound‐image or written mark) and its signified (or concept) is described as ‘unmotivated’ or arbitrary because there is no natural or necessary bond between them, only the convention of a given language. The same applies to the relationship between the sign and the object to which it refers. The arbitrariness of these relationships can be shown by comparing the ways in which different languages allocate signifiers to signifieds. Some theorists point out that the sense of randomness attached to the term is misleading, and that the term ‘conventional’ is preferable.