interjection / noun / adjective
blah
BLAH/blˈɑ/
Dull and lacking interest or meaning.
The endless presentation leaves everyone feeling blah by the afternoon break.

Etymology
Blah probably imitates empty talk and is recorded as meaning “idle, meaningless talk.” Its related adjective means “dull,” matching its use to express boredom or dismissal.
In context
go that way. You're going to pass Toy Story Land, blah blah blah.
More examples
- The speech was full of empty blah.
- “Blah,” she says, dismissing the familiar excuse.
- The room looks rather blah without any color.
Similar words
- dull
- Uninteresting without the informal expressive tone.
- listless
- Lacking energy, matching the personal-state use rather than empty talk.