lapillus
/ləˈpɪləs/
noun
- A small fragment of volcanic rock ejected during an eruption, usually between 2 and 64 millimeters in diameter.
- Hikers on the volcanic slope had to watch their step on the loose lapilli.
- The geologist collected a sample of lapillus to study the volcano's history.
- After the volcano erupted, the ground was covered with lapilli that looked like tiny pebbles.
Synonyms