Plurale tantum

pluralia tantum) is a noun that appears only in the plural form and does not have a singular variant for referring to a single object.

In English, pluralia tantum are often words that denote objects that occur or function as pairs or sets, such as spectacles, trousers, pants, scissors, clothes, or genitals.

Other examples include suds, jeans, outskirts, odds, riches, gallows (although later treated as singular), surroundings, thanks, and heroics.

A bilingual example is the Latin word fasces that was brought into English; when referring to the symbol of authority, it is a plurale tantum noun in both languages.

Others like "nothingness" or "emptiness" refer to logical states of absence that can't sensibly be quantified at all, hence are not usefully "mass nouns" but are still Singularia Tantum.

In some other languages, rather than quantifying a plurale tantum noun with a measure word, special numeral forms are used in such cases.

In Polish, for example, "one pair of eyeglasses" is expressed as either jedne okulary (one-plural glasses-plural) or jedna para okularów (one-singular pair-singular glasses-genitive plural).

Compare them to the ordinary numeral forms found in Polish: trzy filmy/pięć filmów (three films/five films)[4] The Russian деньги (den'gi, 'money') originally had a singular, деньга (den'ga), which meant a copper coin worth half a kopeck.