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.
1. Qui ne peut être perçu.
2. Infime.
Impossible ŕ discerner. Différence indiscernable entre jumeaux.