tephra
TEF-rah
The general term for all solid material ejected into the air by a volcanic eruption — ash, pumice, cinders, bombs, and blocks, regardless of size, composition, or distance traveled. Tephra ranges from fine dust that circles the globe to car-sized boulders that land within a mile of the vent. It is the word that contains the entire spectrum of volcanic fallout.
Etymology
Greek tephra, ash, from tephros, ash-colored. The word was adopted by volcanologists in the mid-20th century to replace the ambiguous and misleading older terms.
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