invariant noun
Definition - Nouns that do not change inflection when pluralized (e.g. moose, salmon, Japanese, and sheep).

1. They are not the same as pluralia tantum (such as bagpipes), which are words that are only used in the plural. They also are different that uncountable nouns (such as furniture) because they can be counted (e.g. one Japanese, two Japanese, …).

Please comment