| Singular | Plural | |
|---|---|---|
| Nominativ | rhomphaea | rhomphaeae |
| Genitiv | rhomphaeae, rhomphaeai | rhomphaeum, rhomphaearum |
| Dativ | rhomphaeae, rhomphaeai | rhomphaeis, rhomphaeabus |
| Akkusativ | rhomphaeam | rhomphaeas |
| Ablativ | rhomphaea, rhomphaead | rhomphaeis, rhomphaeabus |
| Vokativ | rhomphaea | rhomphaeae |