a rotund individual
"The coach hesitated to call the fatty into action because his bulk made him slower than everyone else on the field."
An obese person.
"The fatty sat in the front row, taking up all three seats and blocking the view of everyone behind him."
Containing, composed of, or consisting of fat.
"The fried chicken was very fatty and left a heavy coating on my lips after I finished eating it."
In plain English: Fatty means having an excessive amount of fat, usually referring to food that is high in calories and unhealthy oils.
"The fatty meat was very crispy and delicious when fried."
Usage: Use this adjective to describe food that contains high levels of dietary fat rather than referring to the physical build of people or animals. It is often confused with similar terms like "greasy," which implies a slick texture from oil on surfaces instead of inherent nutritional content.
The word "fatty" comes from Middle English by adding the suffix -y to fat. It is related to similar words in Frisian and Dutch that also describe something fatty or greasy.