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am·phi·bole

(ămfə-bōl′)

Any of a large group of structurally similar silicate minerals, such as hornblende, that have a crystalline structure consisting of a double chain of linked SiO₄ units and that contain various combinations of sodium, calcium, magnesium, iron, and aluminum. Several varieties of asbestos are fibrous forms of amphiboles.

[French, from Late Latin amphibolus, ambiguous, from Greek amphibolos, doubtful, from amphiballein, to throw on either side : amphi-, amphi- + ballein, to throw; see g^welə- in the Appendix of Indo-European roots.]

am′phi·bolic (-bŏlĭk) adj.

Indo-European & Semitic Roots Appendices

Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:

Indo-European Roots

Semitic Roots

The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.

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