bílsins

Bílsins is the definite genitive singular form of the Icelandic noun bíll, which means car. It translates roughly as "the car's" or "of the car" and is used to indicate possession or a close association within a noun phrase. In standard Icelandic noun inflection, the base form bíll forms the genitive singular bíls, and the definite genitive singular is bílsins.

The form bílsins appears in phrases such as verndmæti bílsins (the car's value) or útboð bílsins (the car's auction). It is typically not used as a standalone word; rather, it functions within noun phrases to show ownership or association. The use of the definite genitive is part of Icelandic grammar for masculine singular nouns and follows the regular pattern of forming a genitive stem plus the definite-genitive ending.

Etymology-wise, bíll is a native Icelandic noun with roots in the Germanic language family and related cognates in other North Germanic languages. The definite genitive form bílsins reflects regular inflectional patterns in Icelandic for masculine nouns, where the genitive stem ends in -s and the definite genitive adds -ins.

In summary, bílsins is a key grammatical form in Icelandic for expressing possession concerning a singular, definite noun bíll (car). Its usage is mainly demonstrated in formal writing, dictionaries, and descriptions of linguistic grammar, rather than in everyday speech, where speakers often rely on possessive pronouns or the noun phrase with a possessive determiner.