durain

[doo r-eyn, dyoo r-]

noun Mineralogy.

the coal forming the dull layers in banded bituminous coal.

Compare clarain, vitrain.

Origin of durain

1915–20; < Latin dūr(us) hard + -ain, from fusain, by analysis as a suffix
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019