shale

 
Pronunciation: /ʃeɪl/

noun

[mass noun]
  • soft finely stratified sedimentary rock that formed from consolidated mud or clay and can be split easily into fragile plates.

Derivatives

shaly

(also shaley) adjective (shalier, shaliest)

Origin:

mid 18th century: probably from German Schale; related to English dialect shale 'dish' (see scale2)