Possible Clues:

• Biting quality
• Bitterness shown by a nomadic tribe in Cyprus
• Acrimony, bitterness
• Sharp/forthright manner
• Bitterness of a tribe lost in deserted city
• Bitterness? In a European, say, it's unknown
• Sharpness was effective cutting very fine line
• Endless bacteria about with unknown virulence
• There's enough sharpness here to confuse confederate soldier in a large town
• Tartness