Merriam-Webster Collegiate Dictionary - asbestos

 noun  Etymology: Middle English albeston mineral supposed to be inextinguishable when set on fire, probably from Middle French abeston, from Medieval Latin asbeston, alteration of Latin ~, from Greek, unslaked lime, from ~ inextinguishable, from a- + sbennynai to quench  Date: 1607 any of several minerals (as chrysotile) that readily separate into long flexible fibers, that cause ~is and have been implicated as causes of certain cancers, and that have been used especially formerly as fireproof insulating materials ASBESTOSIS  noun  (plural asbestoses)  Date: 1927 a pneumoconiosis due to asbestos particles that is marked by thickening and scarring of lung tissue