'Custom' in the Bible

And some men came down from Judea [and] began teaching the brothers, "Unless you are circumcised according to the custom [prescribed] by Moses, you cannot be saved."

{And as was his custom}, Paul went in to them and on three Sabbath [days] he discussed with them from the scriptures,

To {them} I replied that it was not the custom of the Romans to give up any man before the one who had been accused met [his] accusers face to [face] and received an opportunity for a defense concerning the accusation.