Dull

The film is dull
That film was really dull as dishwater

Tedious

Too long, slow and boring
My commute is so tedious

Boring and serious
This book is really dry.
The conversation was really dry.

Boring and lacking in variety

Boring because nothing changes
A town/city/village could be humdrum. 无趣的
I’ve moved to a really humdrum town in Wales.

very boring

boring because it has no flavour
my cooking is definitely not bland.

Boring and lacks excitement

Boring in a depressing way
Weather could be dreary, if it is raining a little bit
The weather is really dreary
He lived a very dreary life.

Boring and lacking in colour
That outfit is a bit drab. I think we need a bit of colour.

Easily forgotten because it is boring/lacking excitement
I went to a play the other day and it was entirely forgettable.

idiom
That football match was like watching paint dry.
I’d rather watch paint dry.