(1):

(n. pl.) In the southern and western parts of the United States, the portion of the hog between the ham and the shoulder; bacon; - called also middles.

(2):

(n. pl.) A combination of the coarser parts of ground wheat the finest bran, separated from the fine flour and coarse bran in bolting; - formerly regarded as valuable only for feed; but now, after separation of the bran, used for making the best quality of flour. Middlings contain a large proportion of gluten.