Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun tedium

2 senses of tedium

Sense 1
boredom, ennui, tedium -- (the feeling of being bored by something tedious)
       => dissatisfaction -- (the feeling of being displeased and discontent; "he was never slow to express his dissatisfaction with the service he received")

Sense 2
tediousness, tedium, tiresomeness -- (dullness owing to length or slowness)
       => dullness -- (the quality of lacking interestingness; "the stories were of a dullness to bring a buffalo to its knees")