DictionaryimperceptibleToo slight to notice
adjective

imperceptible

im-pur-SEP-tuh-buhl/ˌɪmpərˈseptəbl/

Too slight or subtle to be noticed.

The tiny ripple is nearly imperceptible until the magnified view reveals it.

Two identical-looking clear water glasses, one containing an almost invisible tiny ripple; magnifying inset reveals the slight ripple.
Etymology

The pieces mean “not capable of being perceived.” In the selected sense, something may exist or happen but be too slight to register with the senses.

In context

TRUE GLOBE38:47
The movement is subtle, almost imperceptible, yet continuous. Never twice does the same thing appear at this lake.
SIBERIA: The Land That Makes Russia More Mysterious | 4K Travel Documentary

More examples

  • The difference between the two shades is almost imperceptible.
  • She gives a nearly imperceptible nod.
  • The crack is imperceptible to the naked eye.

Forms

imperceptible

imperceptibly adverb — In a way that escapes notice.

Similar words

subtle
Difficult to notice, but not necessarily beyond human perception.
undetectable
Emphasizes inability to discover something through observation or testing.