What's the point of doing that of she has no idea what it means?. I suppose in one scenario she finds out because some guy hits on her and tells her and she totally is into the idea. But let's be honest, that is most likely husband fantasy land.
The other scenario is she finds out because someone tells her, maybe guys started hitting on her but she does not like the unwanted attention , maybe the guy or guys are not nice, not ones your wife would be flattered being hit on by, etc. how does that scenario play out? Or maybe just some one in your friends group knows the meaning (without being in the lifestyle) and starts telling everyone that you two are and it does not sit well with them or maybe her work finds out and it creates problems.
See how this type of dishonestly can be dangerous?
You know what might work better? Open honest communication with her, where you both feel safe, being a great lover and making her feel desired and attractive, making her feel safe talking about fantasies (without pressure to live them all out).
Try that.