unnoticeable

US /ˌʌnˈnoʊ.t̬ɪ.sə.bəl/
UK /ˌʌnˈnoʊ.t̬ɪ.sə.bəl/
1.

không thể nhận ra

difficult or impossible to notice:

:
•
Digital hearing aids are available that are so tiny as to be virtually unnoticeable.