C1 adjective ˌɪm.pəˈsɛp.tɪ.bəl
imperceptible
अदृश्य
Meaning
So subtle or gradual that it is difficult to notice or perceive
Example
The changes in his behavior were imperceptible at first.
उसके व्यवहार में परिवर्तन पहले पहले अदृश्य थे।