fatten

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

We must fatten the turkey in time for Thanksgiving.

And if the mat[t]er be too little, the vertue of digestion fayleth, and the bodye is dryed, and if the matter and meate be moderate, the meats is well digested, and the bodye fattened, the heart comforted, kinde heate made more, the humors made temperate, & wit made cleere:

To become fat or fatter.

He gradually fattened in the five years after getting married.

The Laplanders, possessing a country where corn will not grow, make bread of the inner bark of trees; and Linneus reports, that swine there fatten on that food […]

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

“You horrible old man, you’ve always tried to turn Erik into a slave, to fatten your pocketbook! […]”

[…] stirred by the air / That freshened from the window, these ascended ⁠/ In fattening the prolonged candle-flames, / Flung their smoke into the laquearia, / Stirring the pattern on the coffered ceiling.

To become thick or thicker.

A broad river of white paper rushed constantly up from the cylinder and leaped into a mangling chaos of machinery whence it emerged a second later, cut, printed, folded and stacked, sliding along a board with a hundred others in a fattening sheaf.

The pencil-line of light by his feet fattened to a bar. Alan looked around and saw Norris Ridgewick.

To make (soil) fertile and fruitful.

to fatten land

1612, Joseph Hall, Contemplations vpon the Principall Passages of the Holie Storie, London: Sa. Macham, Volume 1, Book 4, p. 333, As the riuer of Nilus was to Egypt in steed of heauen to moisten and fatten the earth; so their confidence was more in it then in heauen;