Synonyms of the word

indiscernible

• adj. Not capable of being discerned, of being perceived.
• adj. Not capable of being distinguished from something else.
• n. (chiefly philosophy) Something which is incapable of being discerned.

imperceptible

• adj. Not perceptible, not detectable, too small in magnitude to be observed.

insensible

• adj. Unable to be perceived by the senses.
• adj. Incapable or deprived of physical sensation.
• adj. Unable to be understood; unintelligible.
• adj. Not sensible or reasonable; meaningless.
• adj. Incapable of mental feeling; indifferent.
• adj. Incapable of emotional feeling; callous; apathetic.

undetectable

• adj. Unable to be detected; not detectable.

unperceivable

• adj. Not perceivable; imperceptible.