It's perfectly correct. Violer is the verb "to rape"; conjugated into the 3rd person, singular past tense, it's viola.

But also it's a violet, and a musical instrument.

I can't imagine many contexts where the three usages would be likely to be confused.

I can't imagine many contexts where the three usages would be likely to be confused

There's this sweet innocent female musician (bit of a shrinking violet type) walking down the street carrying her viola ... and this French guy wants to rape her ...

(Hmmm, might have the potential but a bit contrived, perhaps.)

Cheers,
Rob