Where does “stomach acid” come from?

stomach acid (English) comes from English acid, from French acide, from Latin acidus, from Latin aceō, from Proto-Italic akēō, from Proto-Indo-European h₂eḱ-éh₁-ye-ti, from Proto-Indo-European h₂eḱ- — sharp.

Ancestry of “stomach acid”, step by step

stomach acid traces back through two separate lines of ancestry.

via English acid

StepLanguageWordMeaning
1EnglishacidSour, sharp, or biting to the taste; tart; having...
2Frenchacideacid, acidic, sour, tart; acid, acidic; acid
3Latinacidussour, tart, acid, bitter; harsh, grating, rough,...
4Latinaceōto be sour
5Proto-Italicakēōbe sharp-tasting, be sour
6Proto-Indo-Europeanh₂eḱ-éh₁-ye-ti
7Proto-Indo-Europeanh₂eḱ-sharp

via English stomach

StepLanguageWordMeaning
1EnglishstomachAn organ in animals that stores food in the...
2Middle EnglishstomakThe stomach or guts of a organism; One's belly;...
3Old Frenchestomacstomach
4Latinstomachusgullet, alimentary canal; stomach; taste or...
5Ancient Greekστόμαχοςthroat, gullet; stomach; bladder
6Ancient Greekστόμαmouth; face; The source of a river or stream
7Proto-Indo-Europeanstomn̥
Every word from Proto-Indo-European h₂eḱ-
stomach acid — Etymology, Origin & Word History | Etymology Explorer