fattening

To cause (a person or animal) to be fat or fatter.

“We must fatten the turkey in time for Thanksgiving.”

(of a person or animal) To become fat or fatter.

“He gradually fattened in the five years after getting married.”

To make thick or thicker (something containing paper, often money).

To become thick or thicker.

To make (soil) fertile and fruitful.

“to fatten land”

To become fertile and fruitful.

The act of making something fatter, particularly in reference or allusion to livestock.

The act of becoming fatter.

That causes weight gain; often of high calorie food with relatively little nutritive value.