Source : Webster's Revised Unabridged Dictionary (1913)

Blet \Blet\, v. i. [imp. & p. p. {Bletted}; p. pr. & vb. n.
   {Bletting}.]
   To decay internally when overripe; -- said of fruit.

Blet \Blet\, n. [F. blet, blette, a., soft from over ripeness.]
   A form of decay in fruit which is overripe.