The Collaborative International Dictionary of English v.0.48:
ambiversive \ambiversive\ adj. 1. (Psychol.) intermediate between introversive and extroversive. Contrasted to introversive and extroversive. [WordNet 1.5]WordNet (r) 3.0 (2006):
ambiversive adj 1: intermediate between introversive and extroversive [ant: extraversive, extroversive, introversive, introvertive]