Well, until I read this comment thread, I wasn't aware that there was an ambiguity with that, either. "Spice" is synonymous with "spices".

I thought the ambiguity was the difference between "spicy" and "spiced", where people often use "spicy" to mean "hot", and "spiced" to mean "contains spices", but not necessarily hot.

Now that I'm aware that others find ambiguity, I have nothing I can say about it because this is new information to me. I suppose it's up to them to define it!