Synonyms for Piercing (same or very similar meaning)
WordNet sense 1 (having or demonstrating ability to recognize or draw fine distinctions):
acute, discriminating, incisive, keen, penetrating, penetrative, knifelike
WordNet sense 2 (having the ability to perceive or understand; keen in discernment):
perceptive
WordNet sense 3 (having or emitting a high-pitched and sharp tone or tones ):
shrill
WordNet sense 4 (used of sounds and voices; high in pitch or frequency):
high
WordNet sense 5 (as physically painful as if caused by a sharp instrument):
cutting, stabbing, lancinate, lancinating
WordNet sense 6 (keenly and painfully felt; as if caused by a sharp edge or point):
sharp
WordNet sense 7 (having an unpleasant sound):
cacophonous, cacophonic
From the ODE community, based on WordNet
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