The interpretation of an utterance is not always derived from the meaning of the single signs. Sometimes, a non-literal interpretation may be involved: those cases are known as figurative meanings.
Well-studied forms of non-literal meanings are metaphors and metonymies. These phenomena are generally identified as poetic devices. However, in recent studies, metaphor and metonymy are also conceived of as broader cognitive mechanisms which are important for the building of everyday life meaning.
In sign languages, metaphors are very frequent since in the visual-gestural channel it is possible to map abstract concepts to concrete concepts. A clear example of this linguistic mechanism is the sign understand in LIS which is realised by the action of grabbing something close to the forehead. In this case, the concrete gesture of grabbing something metaphorically recalls the idea of grabbing a concept.
understand
Metonymy is another non-figurative strategy which creates a relation between two concepts or entities, by considering a specific association or a particular continuity between them. The possible metonymic relationships may involve the substitution of a part for the whole, a place for an institution, the author for his/her writing, the container for the product, and so forth.
Metonymic processes are not only used as rhetorical strategies, but also as a more common mechanism of word construction in LIS. Some frozen signs have undergone a metonymic process: for example, the sign house is built upon the classifier for root. In this case, the root, which is a part of the whole entity, becomes the sign for referring to the general concept of the house.
house