Déclinaison / Conjugueur latin
| SINGULIER |
| Nom. | fideicommissarius |
| Gen. | fideicommissarii |
| Dat. | fideicommissario |
| Acc. | fideicommissarium |
| Abl. | fideicommissario |
| Voc. | fideicommissarie |
| PLURIEL |
| Nom. | fideicommissarii |
| Gen. | fideicommissariōrum |
| Dat. | fideicommissariis |
| Acc. | fideicommissarios |
| Abl. | fideicommissariis |
| Voc. | fideicommissarii |
| SINGULIER |
| Nom. | fideicommissariă |
| Gen. | fideicommissariae |
| Dat. | fideicommissariae |
| Acc. | fideicommissariam |
| Abl. | fideicommissariā |
| Voc. | fideicommissariă |
| PLURIEL |
| Nom. | fideicommissariae |
| Gen. | fideicommissariārum |
| Dat. | fideicommissariis |
| Acc. | fideicommissarias |
| Abl. | fideicommissariis |
| Voc. | fideicommissariae |
| SINGULIER |
| Nom. | fideicommissarium |
| Gen. | fideicommissarii |
| Dat. | fideicommissario |
| Acc. | fideicommissarium |
| Abl. | fideicommissario |
| Voc. | fideicommissarium |
| PLURIEL |
| Nom. | fideicommissaria |
| Gen. | fideicommissariōrum |
| Dat. | fideicommissariis |
| Acc. | fideicommissaria |
| Abl. | fideicommissariis | |