Obese means very much overweight, to the point of harm. Clinically obese, an obese patient, becoming obese.
It is a clinical term with a threshold — a body mass index of thirty or more — which is why it appears in medical writing where fat would not. The measure is crude and misclassifies muscular people, and it is used anyway because it is cheap. Note that the Latin means eaten away, oddly, from a verb meaning to devour.
1adjectiveobeseVery much overweight, to the point of harm.
“Doctors warned that the obese man needed to lose weight before his operation.”
obese is a state of excess weight.
Latin obesus comes from obedere, to devour — ob plus edere, to eat. Edible and comestible come from the same eating.
Proto-Indo-European
*h₁ed-
Latin
obēsus
English, today
obese
Built from
From Latin obēsus, derived from obedō (“to devour, eat away”), from ob (“away”) + edō (“to eat”).
Etymology from Wiktionary, CC BY-SA