The Collaborative International Dictionary of English v.0.48:
adamance \adamance\ n. 1. same as adamancy. Syn: obstinacy, obduracy, unyieldingness, adamancy [WordNet 1.5 +PJC]WordNet (r) 3.0 (2006):
adamance n 1: resoluteness by virtue of being unyielding and inflexible [syn: adamance, obduracy, unyieldingness]