IPA: /ˈstʌməkˌeɪk/
KK: /ˈstʌməkˌeɪk/
A feeling of pain or discomfort in the area of the stomach or abdomen.
After eating too much candy, I had a terrible stomachache.
Stomachache → It is formed from "stomach" (from Old French *estomac*, meaning the organ that digests food) and "ache" (from Old English *æce*, meaning pain or discomfort). The word "stomachache" refers to pain or discomfort in the stomach area.
Think of the word 'stomach' as the organ where food is digested, and 'ache' means pain. So, a stomachache is simply pain in the stomach.
No commonly confused words.