na-adjective, noun
monotonous; dull; lacking variety
Describes something repetitive and unchanging, often with a negative connotation. Used for speech, music, daily life, landscapes, etc.
彼の話し方は単調で、すぐに眠くなった。
His way of speaking was monotonous, and I soon got sleepy.
毎
With the same tasks repeated every day, life feels monotonous.
noun, na-adjective
monotone; monotonic
Mathematics term for a function or sequence that never decreases or never increases.
この関数は単調増加である。
This function is monotonically increasing.