Non-emblematic manual gestures pose a double challenge for semantic theories: Firstly, gestures are instances of visual communication, so their interpretation requires a means of perceptual classification. Secondly, according to gesture studies, non-emblematic gestures lack “standards of form” (McNeill, 1992, p. 22). In other words, there is no lexicon of such gestures (as opposed to emblematic ones). Accordingly, the linguistic interpretation of gestures – that is, the classification of a gesture occurrence by means of verbal labels from a natural language – leaves room for interpretation. If this room for interpretation is to be resolved, it must be negotiated in dialogue (“What does the speaker/gesturer mean by the gesture?”). Therefore, the linguistic meaning of non-emblematic gestures, if unclear or important for the understanding of the utterance, must be agreed in dialogue.