/ˌɪmpəˈseptəbl ||; ˌɪmpɚˈsɛptəbḷ/adj too small to be seen or noticed 难以察觉的:
The difference between the original painting and the copy was almost imperceptible. 原画与摹本几乎一模一样，实在难分真假。 [OPP] perceptible 反义词为perceptible➔imperceptibly /-əbli ||; -əblɪ/ adv Almost imperceptibly winter was turning into spring. 冬去春来，季节交替竟是这样无声无息。