The title is actually a triple pun, making the Slovak translator's choice an unfortunate one.
'
Earnest,' aside from being a perfectly regular adjective and proper name, was also
Victorian underworld slang for gays ("Oh him? I hear that he's terribly earnest.").
One imagines that
Oscar Wilde would have been beside himself to see such a coded reference up in lights all over the
West End of London.
I think that, in stripping the word "earnest" from the play, one unavoidably removes much of 's subtext, which deals with gay men living under the hypocritical and hostile cultural taboos of Victorian England.