[am.phi.bole] n [F, fr. LL amphibolus, fr. Gk amphibolos ambiguous, fr. amphiballein to throw round, doubt, fr. amphi- + ballein to throw--more at devil] (ca. 1823) 1: hornblende
2: any of a group of complex silicate minerals with like crystal structures that contain calcium, sodium, magnesium, aluminum, and iron ions or a combination of them