undetectable

英[ˌʌndɪ'tektəbl] 美[ˌʌndɪ'tektəbl] adj. 覺察不到的；發現不了的

undetectable是英語單詞。

Adjective:

not easily seen

barely able to be perceived;

"the transition was almost indiscernible" "an almost insensible change"

1.

not easily seen

2.

barely able to be perceived;

"the transition was almost indiscernible" "an almost insensible change"