In researching the term '(articulatory) gesture', it seems to me that the meaning is something like 'movement of a single articulator for a single segment'. Ergo, e.g. a sound with secondary articulation would consist of (at least) two gestures. This seems to be the definition used here, for example. However, I've also seen usage which seems to suggest it means 'movement of all articulators involved in the formation of a segment'.
Is this a case of one usage being wrong? Of disagreement or polysemy existing in the literature?