From Longman Dictionary of Contemporary Englishfatfat1 /fæt/ ●●●S1W2 adjective (comparative fatter, superlative fattest)1fleshFATweighing too much because you have too much flesh on your body opp thinAre you suggesting I’m too fat?a short fat man in his early fiftiesYou’ll get fat if you eat all that chocolate.He looks much fatter than in his photo.2objectTHICK OBJECT OR MATERIALthick or wide opp thinDobbs was smoking a fat cigar.a big fat book3money [only before noun] informalLOT/LARGE NUMBER OR AMOUNTcontaining or worth a large amount of moneya fat chequeOf course the supermarkets’ aim is to make fat profits.4 →fat chance5 →(a) fat lot of good/use6 →fat cat7 →in fat city8 →grow fat on something9 →a fat lip10approval informal another spelling of phat – used to show approval, especially of someone or something that is fashionable, interesting, or attractivefat/phat beats (=music that sounds good)Check out these fat beats. —fatness noun [uncountable]a rise in fatness in childrenTHESAURUSfat having too much flesh on your body. It is rude to tell someone that they are fat. It is also better not to use any of these words when talking directly to someone about their bodyShe thinks she’s fat.He looks the same, just a little fatter.overweight weighing more than you shouldMany medical conditions are caused by being overweight.She was several kilos overweight.big/large used when saying that someone has a big body. Large is more common than big in written EnglishMy father was a big man.two large ladiesobese extremely fat in a way that is dangerous to your healthHe went to a summer camp for obese teenagers.chubby slightly fat in a nice-looking way – used especially about babies and childrenA chubby little baby was playing on the rug.plump a woman or child who is plump is slightly fat, especially in a pleasant wayHer mother was a plump cheerful woman.flabby having softlooseskin that looks unattractivea flabby stomachHer body was getting old and flabby.portly literary fat and round – used especially about fairly old menThe bishop was a portly middle-aged gentleman.
fatfat2 ●●●S2W2 noun1[uncountable]HBA a substance that is stored under the skin of people and animals, that helps to keep them warmRolls of fat bulged over his collar.I didn’t like the meat – there was too much fat on it.2[countable, uncountable]DFN an oily substance contained in certain foodsCream has a high fat content.high/low in fatThis cheese is relatively low in fat.You should think about reducing your fat intake (=the amount of fat you eat).high-fat/low-fata low-fat diet →saturated fat3[countable, uncountable]DFC an oily substance taken from animals or plants and used in cookingPlace the chicken in the hot fat.4 →the fat is in the fire5 →live off the fat of the land6 →run to fat → chew the fatat chew1(4), → puppy fat