un·detect·ableBrE /ˌʌndɪˈtektəbl/ 🔊NAmE /ˌʌndɪˈtektəbl/ 🔊 adjectiveimpossible to see or find 看不见的；察觉不出的；发现不了的◆The sound is virtually undetectable to the human ear. 这声音实际上是人耳难以听得到的。🔊🔊 OPP detectable