ETYM Pref. im- not + perceptible: cf. French imperceptible.
Impossible or difficult to perceive by the mind or senses; SYN. unperceivable.
ETYM Pref. in- not + appreciable: cf. French inappréciable.
Too small to make a significant difference.
ETYM Pref. in- not + discernible: cf. French indiscernable.
1. Barely able to be perceived; SYN. insensible, undetectable.
2. Difficult or impossible to perceive or discern.
Not capable of being distinguished or differentiated; SYN. undistinguishable.
In an imperceptible manner or to an imperceptible degree; SYN. unnoticeably, observably.
Imperceptibly; insignificantly, in an unimportant manner, trivially
Indiscriminately; so as to be impossible to differentiate
In an undiscernible manner, imperceptibly, in a manner than cannot be sensed