It's a Finnish interjection for
disappointment, often used in a humorous sense to describe a
small unpleasant surprise.
It's also been used to prove hopes or thoughts wrong and mislead, or to express the
stupidity of something as an idea.
The volume and tones of pronouncing the word makes a difference to the meaning, of course.
"My credit card expired
today"
"Höh!"
"Höh, ette te kanssa mitään tiedä!"
= "Höh, I thought you knew
something but you
don't know shit!"