in the PONS Dictionary
| Case | Singular |
|---|---|
| Nominative | Cycnus |
| Genitive | Cycnī |
| Dative | Cycnō |
| Accusative | Cycnum |
| Ablative | Cycnō |
| Case | Singular | Plural |
|---|---|---|
| Nominative | cycnus | cycnī |
| Genitive | cycnī | cycnōrum |
| Dative | cycnō | cycnīs |
| Accusative | cycnum | cycnōs |
| Ablative | cycnō | cycnīs |