From a Proto-Indo-European *Her-, with original sense and exact identity of the laryngeal *H- uncertain, though Avestan (arәnu-, “battle”) appears to be a semantically appealing cognate.[1] The identity of the Indo-European root, including specified laryngeal, may be *h₃er- (“to move, stir; to rise, spring”), based on cognates that Orel adduces, such as Sanskrit अर्ण (árṇa, “(undulating, surging) water”), Ancient Greek ὄρνῡμῐ (órnūmi, “to set into motion”).[2]
*arniz[1]
| Strong declension | ||||||
|---|---|---|---|---|---|---|
| Case | Masculine | Feminine | Neuter | |||
| Singular | Plural | Singular | Plural | Singular | Plural | |
| Nominative | *arnjaz | *arnjai | *arnjō | *arnjôz | *arnją, -atō | *arnjō |
| Accusative | *arnjanǭ | *arnjanz | *arnjǭ | *arnjōz | *arnją, -atō | *arnjō |
| Genitive | *arnjas, -is | *arnjaizǫ̂ | *arnjaizōz | *arnjaizǫ̂ | *arnjas, -is | *arnjaizǫ̂ |
| Dative | *arnjammai | *arnjaimaz | *arnjaizōi | *arnjaimaz | *arnjammai | *arnjaimaz |
| Instrumental | *arnjanō | *arnjaimiz | *arnjaizō | *arnjaimiz | *arnjanō | *arnjaimiz |
| Weak declension | ||||||
| Case | Masculine | Feminine | Neuter | |||
| Singular | Plural | Singular | Plural | Singular | Plural | |
| Nominative | *arnjô | *arnjaniz | *arnjǭ | *arnjōniz | *arnjô | *arnjōnō |
| Accusative | *arnjanų | *arnjanunz | *arnjōnų | *arnjōnunz | *arnjô | *arnjōnō |
| Genitive | *arnjiniz | *arnjanǫ̂ | *arnjōniz | *arnjōnǫ̂ | *arnjiniz | *arnjanǫ̂ |
| Dative | *arnjini | *arnjammaz | *arnjōni | *arnjōmaz | *arnjini | *arnjammaz |
| Instrumental | *arnjinē | *arnjammiz | *arnjōnē | *arnjōmiz | *arnjinē | *arnjammiz |