sludge acid
Impure dark-coloured sulphuric acid that has been used in the refining of petroleumImpure dark-coloured sulphuric acid that has been used in the refining of petroleum.
Meaning
1 senses(uncountable)Impure dark-coloured sulphuric acid that has been used in the refining of petroleum.
Lessons for this word
1 lessons- A1Countable and uncountable nouns — Because it can be uncountable