A mapping between form and meaning in which the form in some way reflects or diagrams the conceptual structure it expresses (e.g., forms for meanings that ‘belong together’ conceptually are positioned close together in a sentence). There is debate over the extent to which grammar is iconic: for those within the generativist framework, iconicity is marginal (sound symbolism as in ‘cuckoo’ would be an example) and most form-meaning mappings are considered arbitrary, whereas for those who take a cognitive-functional approach, iconicity is pervasive.
See Cognitive functionalist approach, Form, Form-meaning mapping, Generative grammar approach