This is a long series of ablative absolutes, followed by two main verbs.
Bucca fissa usque ad aures,
With your mouth split all the way up to the ears,
with your gums exposed,
with your nose crushed,
you will be a mask,
et ridebis semper.
and you will always be laughing.
This definitely doesn't look Classical; masca "mask" is a fairly late word, for example, borrowed from Germanic in the 600s. A few of the other words are also unfamiliar.
Genzivis looks like the ablative plural of a word like *genziva that I don't recognize at all. Many sources seem to quote it instead as genezivis, but I don't recognize that either, and can't find it in any dictionaries; it certainly doesn't seem to be a Classical word. This book translates it as "gums" (as in the things holding the teeth; Classical gingivis > French gencive) which makes sense given the context.
Murdridato, similarly, seems to be the participle of a verb like murdridare that I also don't recognize at all. Murdrum is another late loan from Germanic (cognate with English "murder") and so this is probably a verb derived from it, but "crushed" makes more sense for a nose than "murdered". The book linked above gives "battered", but this doesn't seem quite violent enough for a verb derived from murdrum (in modern English at least).