From the Greek Cac- (Bad) + -onym (Name)
You could refer to any name you didn't like as a caconym, but it usually refers to scientific names for plants and animals that are 'bad'. They may be bad because they are a misclassification, because they contain bad grammar, or because it is objectionable for linguistic reasons.
Taphrina cerasi (Fuck.) Sad.: It was first described by Karl Wilhelm Gottlieb Leopold Fuckel, and hence the complete name includes an unfortunate monosylable.
Nessiteras rhombopteryx: A proposed name for the Loch Ness monster. Since the thing doesn't exist(?), this may by some be considered a caconym.
Haliaeetus Savigny: The bald eagle. The double 'e' is a typo, but since it was a typo in the first written record of the name, we are 'required' to keep it.
Variations: caconymic, caconymy, caconymous.
If you liked this, you might also like the words cacophonic, misnomer, and euonym.