| Part of speech | unknown part of speech |
|---|
| Singular | Plural | |
|---|---|---|
| Nominative | diametro | diametroj |
| Accusative | diametron | diametrojn |
| Afrikaans | deursnee; deursneë |
|---|---|
| Catalan | diàmetre |
| Czech | průměr |
| Danish | diameter |
| Dutch | diameter; doorsnede; middellijn; doorsnee |
| English | diameter |
| German | Diameter; Durchmesser; Halbmesser |
| Hungarian | átmérő |
| Luxemburgish | Duerchmiesser |
| Papiamento | diameter |
| Portuguese | diâmetro |
| Saterland Frisian | Diameter; Truchmäite |
| Spanish | diámetro |