This was a woman who definitely doesn't have enough Spanish to have known that meaning. The one you're thinking of is fairly rare slang even for those who are fluent. I've never heard it used in Southern California and suspect its used in Spain rather than the Americas. I've always wondered if there was a split from Latin between cuniculus and cunnus to come up with that slang though. I do have a few friends from Guatemala who also use the word to mean "dummy" or "simpleton". #RandomThingsYouKnowWhenYouHaveAStuffyNamedConejito