Blets,

Chambers's Encyclopaedia, Volume 2: Beaugency to Cataract, p. 223

Blets, rotten spots in apples, pears, medlars, and other fruits.—Bletting is the first stage in the rotting of such fruits when the consistency of the fruit has altered, and the colour changed to brown, but before actual putrefaction has set in. The medlar is eaten in this state. See FRUIT.

Source scan(s): p. 0234