1. So lacking in interest as to cause mental weariness
   "other people's dreams are dreadfully wearisome";
   - boring, deadening, dull, ho-hum [informal], irksome, slow, tedious, tiresome, unamusing, deadly [informal], draggy [informal], mind-numbing

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