The Collaborative International Dictionary of English v.0.48:

Tedious \Te"di*ous\, a. [L. taediosus, fr. taedium. See
   Tedium.]
   Involving tedium; tiresome from continuance, prolixity,
   slowness, or the like; wearisome. -- Te"di*ous*ly, adv. --
   Te"di*ous*ness, n.
   [1913 Webster]

         I see a man's life is a tedious one.     --Shak.
   [1913 Webster]

         I would not be tedious to the court.     --Bunyan.
   [1913 Webster]

   Syn: Wearisome; fatiguing. See Irksome.
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WordNet (r) 3.0 (2006):

tediousness
    n 1: dullness owing to length or slowness [syn: tediousness,
         tedium, tiresomeness]