staling

from The Collaborative International Dictionary of English v.0.48

Stale \Stale\, v. t. [imp. & p. p. {Staled} (st[=a]ld); p. pr. &
   vb. n. {Staling}.]
   To make vapid or tasteless; to destroy the life, beauty, or
   use of; to wear out.
   [1913 Webster]

         Age can not wither her, nor custom stale
         Her infinite variety.                    --Shak.
   [1913 Webster]