* Adjective: Describing something as having a large amount of adipose tissue (e.g., "He's got a fat belly.")
* Noun: Referring to adipose tissue itself (e.g., "Eating too much fat is unhealthy.")
* Verb: To make something larger or thicker (e.g., "He fattened the pigs for market.")
* Interjection: Used as an exclamation (e.g., "Fat chance of that happening!")
To determine the part of speech of "fat" in a particular sentence, you need to consider its role and function.