A mass noun is a noun such as 'wine' which is usually uncount but is used with 'a' or 'an' or used in the plural whenit refers to types of that substance, as in 'a range of Australian wines'.
2. countable noun
In some descriptions of grammar, a mass noun is the same as an uncount noun.
English Easy Learning GrammarNumber in nounsSingular number is used when the noun refers to one item. Plural number is used whenthe noun refers to more than one item. Countable nouns have both singular ... Read more
mass noun in British English
noun
a noun that refers to an extended substance rather than to each of a set of isolable objects, as, for example, water as opposed to lake. In English when used indefinitely they are characteristically preceded by some rather than a or an; they do not have normal plural forms
Compare count noun
mass noun in American English
US
a noun denoting an abstraction or something that is uncountable, and not preceded by a or an: it is typically in a singular construction, but may be singular or plural in form (Ex.: love, girlhood, butter, news)