WordWeb Online

1. So lacking in interest as to cause mental weariness
   "tedious days on the train";
   - boring, deadening, dull, ho-hum [informal], irksome, slow, tiresome, wearisome, unamusing, deadly [informal], draggy [informal], mind-numbing
    
2. Using or containing too many words
   "tedious speakers";
   - long-winded, verbose, windy [informal], wordy

See also: lame, lameo [informal], meh [informal], prolix, samey [Brit, informal], uninspiring, uninteresting, verbal

Encyclopedia: Tedious