Humorousness is an old word bearing the sense jocularity or funniness. It often bears replacement with the shorter, reliable noun humor (humour outside the U.S.), but it works when speaking of funniness in abstract terms or in terms of degrees. Something that has humorousness is funny in perhaps some accidental way, while something that has humor is one that involves intentional funniness. A comedic movie, for instance, has humor, while an awful dramatic movie might have an unintentional humorousness because it is so bad. The line between the two words is blurry, though, and humor would very often work in humorousness‘s place.
And, in spite of its humorousness, the oil painting on panel is virtuosic. [The Wire]
What makes such an unconventional arrangement work so cohesively is that the band seems aware of the humorousness of their setup. [Northern Star Online]
And Clive Wood’s Enobarbus, unravelling from humorousness to desolation, points, as he should, to the heart of the matter. [Guardian]
This disagreement over the humorousness of Hitler is, perhaps, the greatest culture clash between Britain and Germany. [The Times Online]