Possible Clues:

• Word sets of senescent origin
• They're said to be served
• 3 down may lead to one of them that come to a full stop
• After a capital start they come to stop that's full
• Strings of words or periods of imprisonment
• May be passed; the point of each is at the end
• Life and death, for two
• They're served or said
• Having a stop that's full at last, they must be served
• Served with a stop that's full at the end for them