pyroclastic

adjective

py·​ro·​clas·​tic ˌpī-rō-ˈkla-stik 

: formed by or involving fragmentation as a result of volcanic or igneous action

Examples of pyroclastic in a Sentence

Recent Examples on the Web

The eruption started Monday morning, with clouds of gas and ash rising above the volcano as lava and pyroclastic flows rolled down the slopes. — ABC News, 4 Aug. 2026

Based on reconstructions, Jackson estimates that the pyroclastic flows would be moving between 100 and 200 kilometers per hour (60–120 mph). — ArsTechnica, 21 July 2026

Vesuvius famously destroyed Pompeii and Herculaneum in AD 79, but its greatest danger today comes from the sheer number of people living within reach of future pyroclastic flows and ashfall. — Kaif Shaikh, Interesting Engineering, 9 June 2026

Some of the dark scars highlighted in the imagery may still contain heat from Shivelyuch's massive 2023 eruption, which sent huge pyroclastic flows surging across the volcano. — Daisy Dobrijevic, Space.com, 11 May 2026

Word History

Etymology

probably from pyro- + clastic

Note: The term was introduced by the English geologist Joseph Beete Jukes (1811-69) in The Student's Manual of Geology, new edition (Edinburgh, 1862), p. 68: "The word 'ash' is not a very good one to include all the mechanical accompaniments of a subaerial or subaqueous eruption, since ash seems to be restricted to a fine powder, the residuum of combustion. A word is wanting to express all such accompaniments, no matter what their size or condition may be, when they are accumulated in such mass so as to form beds of 'rock.' We might call them perhaps 'pyroclastic materials'… ." In the index pyroclastic is glossed as "broken from fire."

First Known Use

1862, in the meaning defined above

Rhymes for pyroclastic

• anaplastic
• bioclastic
• fibroblastic
• hyperplastic
• hypoplastic
• inelastic
• lymphoblastic
• neoplastic
• orgiastic
• periphrastic
• predynastic
• superplastic