Possible Clues:

• Apply Novocain, e.g.
• An inclusion indeed would make one much less lively
• Blunt, numb
• Dull for 22 down at last
• Damp down; make less sensitive
• If the editor turns up in the Middle East, keep it quiet
• Muffle, make muted
• Muffle, as sound
• Apply novocaine to
• Kill