Linguistic symbols are used in three different types of situations: (1) immediate, (2) displaced, and (3) transferred. [...] The word 'rat' may also be used in a transferred sense, as when someone says, 'That gangster is a rat'. [...] Forms used in a transferred contexts are very difficult to define, for the subjective features of the environment are vitally important.
- Nida (1949), Pag. 161