Word family noun perception perceptiveness adjective perceptible ≠ imperceptible perceptive verb perceive adverb perceptibly ≠ imperceptibly perceptively
From Longman Dictionary of Contemporary Englishimperceptibleim‧per‧cep‧ti‧ble /ˌɪmpəˈseptəbəl $ -pər-/ adjective SMALLalmost impossible to see or notice Such changes are imperceptible to even the best-trained eye. —imperceptibly adverb The daylight faded almost imperceptibly into night. —imperceptibility /ˌɪmpəseptəˈbɪləti $ -pər-/ noun [uncountable]Examples from the Corpus
imperceptible• At first it looked empty, then he saw two small vessels, just short of the horizon, their motion imperceptible.• It leaves us ghosts altogether imperceptible.• Male and female are very similar in appearance; the male is slightly larger, but the difference is usually imperceptible.• To the innocent listener the form must be imperceptible, and bewildering in its lightning succession of perpetually fugitive events.• an almost imperceptible earthquake• When this imperceptible metamorphosis took place, it would not be long before another marriage was arranged.• The result resembles a cyclist pedalling strongly into an equally strong headwind-and wobbling dangerously as almost imperceptible progress is made.• Suddenly, cued by some imperceptible signal, a thousand birds rise as one thing.• The current, usually imperceptible, was making its presence known with little shreds of foam on top of the small waves. 