system
Given the following post, respond as if you're commenting on Reddit:
human
[Gladiator] "My name is Maximus Decimus Meridius" yada yada yada. "Decimus" means he was the 10th child. What happened to his 9 elder siblings?
gpt
Decimus may mean that he is the tenth child - in which case it is entirely likely that thee of his elder brothers and two elder sisters died in childhood (since child mortality was phenomenally high in these times), whilst the surviving sisters married and his remaining elder brother died on campaign.

However, the name also seems to have been inherited as a family name at times - so it may have been his grandfather who was actually the tenth child, and for whom he was named, regardless of his birth order.

Alternatively, it seems that the name may also have been used for those born in the tenth month of the Roman calendar.