Webster's Revised Unabridged Dictionary · 1913

Indigestible

Indigestible , adjective

[Latin indigestibilis: compare French indigestible. See In- not, and Digest.]

1.
Not digestible; not readily soluble in the digestive juices; not easily convertible into products fitted for absorption.
2.
Not digestible in the mind; distressful; intolerable; as, an indigestible simile. — T. Warton