Meaning of rock butter | Babel Free
Definitions
Native alum mixed with clay and iron oxide, usually in soft masses of a yellowish-white colour, occurring in cavities and fissures in argillaceous slate.
uncountable
CEFR level
B2
Upper Intermediate
This word is part of the CEFR B2 vocabulary — upper intermediate level.
This word is part of the CEFR B2 vocabulary — upper intermediate level.