Definition of non-plural in English:
non-plural
noun nɒnˈplʊərəlnɒnˈplʊər(ə)lnɒnˈplɔːrəl
That which is not plural; (Grammar) that which is not in the plural form.
adjective nɒnˈplʊərəlnɒnˈplʊər(ə)lnɒnˈplɔːrəl
That is not plural; (Grammar) that is not in the plural form.
Origin
1940s. From non- + plural.