transcription, транскрипция: [ ˌim-pər-ˈsep-tə-bəl ]
adjective
Etymology: Middle English, from Middle French, from Medieval Latin imperceptibilis, from Latin in- + Late Latin perceptibilis perceptible
Date: 15th century
: not perceptible by a sense or by the mind : extremely slight, gradual, or subtle
imperceptible differences
• im·per·cep·ti·bly -ˈsep-tə-blē adverb