imperceptible

Từ điển WordNet v3.1 - WordNet Dictionary

adjective

impossible or difficult to perceive by the mind or senses
- an imperceptible drop in temperature
- an imperceptible nod
- color is unperceivable to the touch
• Syn:
unperceivable
• Ant:
perceptible
• Similar to:
impalpable, incognizable, incognoscible, indiscernible, insensible,
undetectable, subliminal, unobservable
• See Also:
impalpable, inaudible, unhearable, invisible, unseeable
• Derivationally related forms:
imperceptibility