Ancus Marcius when king of the Romans[1] fortified a place near the remainders(?) and near the outflows of the river Tiber. On the shore itself he set up a city, which he named Ostia from the position; as Greeks might say, a door; I think it lies some sixteen milestones from Rome.[2]
Also [sc. attested is] w)stia/rios with an omega, from [the verb] w)qei=n.
An ostia [is] a door amongst Romans, which gives rise to the rank ostiarius with an omicron.
Let it not be given a Greek etymology!