As an adjective monotonous
is having an unvarying tone or pitch.
As a noun tedium is
boredom or tediousness; ennui.
monotonous
English
Adjective
(
en adjective)
having an unvarying tone or pitch
tedious, repetitious or lacking in variety
Related terms
* monotone
* monotony
Synonyms
* monotonic
* samely
tedium
English
Alternative forms
* (dated)
Noun
(en-noun)
Boredom or tediousness; ennui.
Synonyms
* boredom, drudgery, ennui, tediousness
Related terms
* tedious