noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   A hydrated silicate mineral which expands on heating; it is used in insulation and as a medium for planting. countable, uncountable
2. 2
   any of a group of yellow or brown hydrous silicate minerals having a micaceous structure wordnet

Synonyms

All synonyms

dudleyite

Etymology

From Latin vermiculus (“wormlet”), for its fibrous nature and tendency to expand into worm-like shapes when heated.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.