say it: im-pur-SEP-ti-buhl
imperceptible is an adjective meaning "impossible or difficult to perceive by the mind or senses". It carries one recorded sense.
impossible or difficult to perceive by the mind or senses
“an imperceptible drop in temperature”
“an imperceptible nod”
“color is unperceivable to the touch”
Definitions, synonyms and semantic relations for imperceptible come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.