| Part of speech | unknown part of speech |
|---|
| Singular | Plural | |
|---|---|---|
| Nominative | alkaloido | alkaloidoj |
| Accusative | alkaloidon | alkaloidojn |
| Dutch | alkaloïde |
|---|---|
| English | alkaloid |
| French | alcaloïde |
| German | Alkaloid |
| Hungarian | alkaloid; alkaloida |
| Portuguese | alcalóide |
| Russian | алкалоид |