transcription, транскрипция: [ ɪmpə(r)septɪb(ə)l ]
Something that is imperceptible is so small that it is not noticed or cannot be seen.
Brian’s hesitation was almost imperceptible.
ADJ
• im‧per‧cep‧tibly
The disease develops gradually and imperceptibly.
ADV : usu ADV with v , also ADV adj