Synonyms: indiscernible, insensible, undetectable
Definition: barely able to be perceived
Usage: the transition was almost indiscernible; an almost insensible change
Similar words: imperceptible, unperceivable
Definition: impossible or difficult to perceive by the mind or senses
Usage: an imperceptible drop in temperature; an imperceptible nod; color is unperceivable to the touch
Synonyms: undetectable
Definition: not easily seen
Similar words: unseeable, invisible
Definition: impossible or nearly impossible to see; imperceptible by the eye
Usage: the invisible man; invisible rays; an invisible hinge; invisible mending