Synonyms of 'fatten'
1 grow fatDictionary, spread, expand
The creature continued to grow and fatten.
2 feed upDictionary, feed, stuff
They fattened up ducks and geese.
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to swell or cause to swell, as with a liquid, air, or wind
When you broaden something such as your experience or popularity or when it broadens, the number of things or people that it includes becomes greater.
We must broaden our appeal.
Thesaurus for fatten from the Collins English Thesaurus
If an animal is fattened , or if it fattens , it becomes fatter as a result of eating more.