IPA: /ˌɪndɪˈdʒɛsʧən/
KK: /ɪnˌdɪdʒˈɛsʧən/
A condition where a person feels discomfort or pain in the stomach due to difficulty in digesting food.
After eating a large meal, I often experience indigestion.
Indigestion is formed from "in-" (meaning not) and "digestio" (from Latin, meaning to break down or dissolve). The word refers to the inability to properly break down food in the digestive system.
Think of 'not' being able to 'break down' food — that's why indigestion means difficulty in digesting.