Do you have more context?
Without that, I would guess
-the hearer wasn't really paying attention (e.g., "I was playing video games and only half heard my mother's list of items to pick up at the store. I think she may have wanted lime or maybe thyme.")
-the hearer couldn't hear clearly. (e.g., they're in a really loud place and it's difficult to hear the speaker)
Either way, the hearer isn't really clear about what was said.