Funny enough, Decimus means something similar - ‘Tenth’. A lot of Roman praenomina (first names) were like that. Primus, Secundus, Tertius, Quartus, Quintus, Sextus, Septimus, Octavius, Nonus, Decimus. First through tenth! Not the most creative fellows, the Romans.

In their defense, birth order rarely correlated with their name - Decimus could just as easily be a firstborn child, or the fifth son.