It depends on the country or libretto (play or story used). It can be 'Opera buffo' (Italian),m 'Opera Comique' (French) or 'Comic Opera' (English). also sometimes called 'Light Opera' in English speaking countries.
The operetta
Um, there are a few synonyms: Operetta, Opera Bouffe... each have slightly differing meanings but essential mean an amusing opera. I'm not sure that there's really any reference to length when it comes to opera, but Operettas are generally shorter than full operas.
The tv show was very amusing or that cat fight is very amusing
I find this question amusing.
If it's funny it's amusing
Some of the questions people ask on wiki answers are amusing. I think they way she dances is amusing.
The joke was somewhat amusing.
The soccer game was very amusing!
Amusing Ourselves to Death was created in 1985.
Meg most amusing
They find Meg most amusing
Watching the children trying to solve the puzzle was very amusing.