indigestible
adjective
[ ɪndɪˈdʒɛstɪb(ə)l ]
• (of food) difficult or impossible to digest.
• "haute cuisine was largely indigestible to the majority"
• too complex or awkward to read or understand easily.
• "a turgid and indigestible book"
Origin:
late 15th century: via French from late Latin indigestibilis, from in- ‘not’ + digestibilis (see digestible).