What does the word fatten mean?

Usage examples for fatten

  1. Ducklings kept out of the water, do not take as much exercise and, in consequence, fatten a little more readily. – Ducks and Geese by Harry M. Lamon Rob R. Slocum
  2. Cover tight then and leave standing six weeks longer, so the wine may fatten on the lees. – Dishes & Beverages of the Old South by Martha McCulloch Williams