Improbably means that something is unlikely to happen. When you say that something is improbably funny, you mean that it's not supposed to be funny, but it is.
The story is improbably funny, even though it's true.
The team's improbably high score was the result of a lucky bounce.
adverb
not easy to believe
Synonyms:
1
That's statistically improbable in the extreme.
2
Improbably, unthinkably, they are falling in love.
3
Indeed, the director is not encumbered with improbabilities.
4
That just seems improbably high.
5
The content of this section seems improbable.
6
The derivation sounds improbable in the extreme.
7
The only problem is the improbable title.
8
It's an unwarranted leap from the improbable to the definite.
9
I agree that the figures are improbably precise.
10
Bad press is both improbable and not the end of the world.